In 2019, the Harvard Museum of Comparative Zoology acquired The R. Glenn Northcutt Collection of Comparative Vertebrate Neuroanatomy and Embryology, which comprises an estimated 500,000 histologic sections and whole mounts prepared and mounted on glass slides. Assembled by Professor Northcutt between 1963 and 2014 to reveal the microscopic anatomy of the nervous system and related tissues, the collection additionally includes valuable slide series prepared by other neuroanatomists, including John Black Johnston, Othmar Solnitzky, and David Senn. Most included specimens are serially sectioned whole or partial brains for comparative cytoarchitectonic studies. There also are series of entire heads and hundreds of serially sectioned embryos representing 22 genera for studies of the development of sensory systems and cranial nerves. The collection is scientifically unique in its taxonomic breadth: the more than 240 genera and 270 species included represent all major groups of living vertebrates as well as two key out-groups, acorn worms and cephalochordates. Particular strengths include hagfishes, lampreys, chondrichthyans, basal actinopterygians, basal sarcopterygians (including all genera of lungfishes and the coelacanth, Latimeria), amphibians, and tuatara (Sphenodon), and many families of squamates, turtles, crocodilians, marsupials, and primates. Ongoing curatorial activities are generating digital whole-slide images of most of the collection, which are accessible via the Internet. Here we briefly describe the history of the collection and its scientific importance, methods used to prepare slides, ancillary materials, doctoral and postdoctoral students and visiting scientists who utilized it in their studies, a partial list of publications based on the slides and, finally, a taxonomic inventory of the collection and related information that will facilitate its use in research and education.
INTRODUCTION
Historical slide collections prepared from biological specimens are unique and irreplaceable resources for the study of life on Earth; they are highly prized by researchers and educators (Richardson and Narraway, 1999; Zilles et al., 2011). Although representing essential vouchers for studies conducted over the last 1.5 centuries or more (Williston, 2016), they also provide valuable substrates for contemporary research (Sanger et al., 2015; Brocklehurst et al., 2016; Miyashita, 2016; Yaryhin and Werneburg, 2019). Yet, such collections are extremely fragile and may degrade with time, especially if they do not receive proper care and conservation (Di Giacomo, 2017; Decker et al., 2018). Natural history museums, which are committed to preserving biological specimens in perpetuity, are logical repositories for such materials. In some instances, they may be the only institutions willing to accept slide collections that are “orphaned” after an investigator's retirement or when a university or other host institution is no longer willing to retain them. At the same time, the capacity for such institutions to share these materials with the broader scientific community is being enhanced by the ongoing development of specialized yet cost-effective whole-slide imaging systems and web-based data management platforms, by which high-resolution images of entire slides may be viewed and analyzed remotely via the Internet (Dietrich et al., 2012; Heerlien et al., 2015; Musson et al., 2015; Decker et al., 2018; Allan et al., 2019; Giere et al., 2019).
The Harvard Museum of Comparative Zoology (MCZ) has embarked on a long-term project to acquire, curate, and digitalize historical slide collections and share these data worldwide. One of the largest collections acquired to date is The R. Glenn Northcutt Collection of Comparative Vertebrate Neuroanatomy and Embryology, a unique resource that comprises an estimated 500,000 histologic sections and whole mounts prepared and mounted on glass slides to reveal the microscopic anatomy of the nervous system and related tissues. Assembled by Professor Northcutt between 1963 and 2014 as the substrate for his renowned studies of the evolution and development of the vertebrate nervous system, the approximately 33,000 slides comprise a main neuroanatomical collection, an embryological collection, and a histochemical collection. In total, these materials were prepared from 270 species representing more than 240 genera. Before their relocation to Harvard, these materials were contained in 439 slide boxes that occupied about 90 linear feet of shelving. Most specimens in the Northcutt Collection comprise serial sections mounted on glass microscope slides. The resulting slide series are unique in the array of staining methods used to prepare them, including many beautiful series stained with technically challenging silver-staining methods such as the Bodian method (Bodian, 1936) and the Golgi–Cox method (Humason, 1979; Vints et al., 2019). Other valuable and interesting specimens include stained whole-mounts of skin that were prepared to show the distribution of neuromasts and electroreceptors in the axolotl, Ambystoma mexicanum (see Northcutt, 1990, 1992) and the channel catfish, Ictalurus punctatus (see Northcutt et al., 1994).
Here we provide an overview of the Northcutt Collection, including a comprehensive taxonomic list of its contents. For several slide series we indicate the taxon, specimen type (e.g., whole embryo), developmental stage, histologic preparation (plane of section, section thickness, staining method, etc.), and other features that may be of interest and assistance to potential users. Our goals are to announce the existence and availability of the Northcutt Collection, demonstrate its importance to dozens of published comparative studies of the vertebrate nervous system, and promote its future use in research and education. We contend that it will be especially useful to the current generation of neuroscientists who are using molecular and genetic approaches to elucidate mechanisms underlying evolutionary innovations. We also outline ongoing efforts to digitize the entire Northcutt Collection and serve the resulting high-resolution whole-slide images online.
BRIEF HISTORY OF THE NORTHCUTT COLLECTION
Most slides in the Northcutt Collection are derived from neuroanatomical studies conducted by Prof. Northcutt and his many students, postdoctoral fellows, and professional collaborators. The oldest of these materials, prepared in the early 1960s when Prof. Northcutt was an undergraduate at Millikin University, include sections of brains of a salamander (Ambystoma), lizards (Iguana, Sceloporus), and several mammals (Oryctolagus, Rattus, and Lasiurus). The Collection was further developed during Prof. Northcutt's initial faculty appointment at Case Western Reserve University beginning in 1968. Several series of the living coelacanth (Latimeria chalumnae) and the Australian lungfish (Neoceratodus forsteri) as well as other lungfishes and basal actinopterygians were made at the University of Michigan, where Prof. Northcutt held a faculty position between 1972 and 1986. The numerous histochemical preparations also were made at Michigan. These series include key taxa from across the vertebrate tree such as skates (Raja and related genera), rays (e.g., Potamotrygon), and sharks (e.g., Triakis), as well as marbled bichir (Polypterus palmas), longnose gar (Lepisosteus osseus), tuatara (Sphenodon punctatus), yellow-spotted Amazon River turtle (Podocnemis unifilis), and Virginia opossum (Didelphis virginiana). These series are of exceptional value because of the quality of the histology, the inherent difficulties of preparing histochemical series, and the rarity of some of the taxa included.
A large number of embryological series are most closely associated with Prof. Northcutt's research at Scripps Institution of Oceanography at the University of California San Diego, where he held a faculty appointment from 1986 until his retirement in 2014, when he transitioned to emeritus professor (Fig. 1). Particularly during the late 1980s and 1990s, one of his major research goals was to understand the role of embryonic placodes in the development of the lateral line and electroreceptive systems, taste buds, and cranial nerves. Only a few of the many hundreds of experimental manipulations of placodal development are included in the Northcutt Collection. Among these are the results of lateral line placodal extirpations and homotopic and heterotopic transplantations in the Mexican axolotl (A. mexicanum). By transplanting placodes from wild-type (pigmented) embryos into albino embryos, the migration and fates of placodally derived cells could be assessed by the distribution of dark pigment in skin mounts of the chimeric salamander later in development.
Figure 1.
Prof. R. Glenn Northcutt at the University of California San Diego, November 2014. On the shelves to his left are rows of slide boxes containing a small portion of the Northcutt Collection. Several additional slide boxes are open on the table in front of him. Photo by William E. Bemis.
Finally, the collection also includes slide series prepared by other American and European neuroanatomists, including John Black Johnston (1868–1939), Othmar Solnitzky (1897–1980), and David G. Senn (1940—). Despite their age—some of J. B. Johnston's series were prepared no later than 1910—these slides are still in excellent condition and remain useful for neuroanatomic studies.
In 2014, the entire Northcutt Collection at Scripps was inventoried and then moved to Prof. William E. Bemis's laboratory at Cornell University in Ithaca, New York (Bemis and Northcutt, 2019). In 2019, ownership was transferred to Harvard University and the collection relocated to the MCZ in Cambridge, Massachusetts, where the slides are housed in a secure collections facility and maintained at constant temperature and humidity in lightproof cabinets (Fig. 2). Once at MCZ, slides were transferred from their original boxes onto stainless steel trays, accessioned into the museum's permanent Special Collections department, given unique identifying numbers, and individually barcoded. Whole-slide imaging of the entire collection began in 2021 with support from the U.S. National Science Foundation and the Faculty of Arts & Sciences, Harvard University. Corresponding digital images are accessible online directly via MCZbase, the museum's shared database, and indirectly via MorphoSource, a repository for digital image data hosted by Duke University, Durham, North Carolina.
Figure 2.
(A) Slide cabinets in the Museum of Comparative Zoology; (B) each cabinet holds 600 trays; (C) each tray holds 36 or 72 slides, depending on slide size.
No slides were culled from the Northcutt Collection before its move from Scripps, first to Cornell and then to Harvard. However, a small number of slide series was already on loan to investigators before the initial move. Some of these loans have since been returned and attempts by MCZ curatorial staff to recover the remaining outstanding loans are ongoing. As slides are returned, they are processed as described above. In general, very few slides in the Northcutt Collection are cracked or broken, and those that are damaged remain accessible—and are being digitalized—along with the rest of their series.
SLIDE PREPARATION AND ANNOTATION
Several different specimen fixatives and histological embedding methods were used to prepare slides in the Northcutt Collection. Typically, specimens were perfused with formol–alcohol (alcohol–formalin–glacial acetic acid fixative) or immersed in buffered formalin (Humason, 1979; Presnell and Schreibman, 1997). Most specimens were sectioned with a rotary microtome after being paraffin embedded because of the ease of mounting “ribbons” of paraffin sections and the wide array of methods that can be used to stain them. Some specimens, however, particularly intact embryos or embryonic tissues, were embedded in LKB Historesin (LKB-Produkter AB, Bromma, Sweden) or JB-4w polymer and the sections mounted individually. Such “plastic” sections present outstanding cellular detail but cannot be processed with many of the most important stains used for conventional neuroanatomy. Specimens for the histochemical series and some in the main collection were embedded in Tissue-Tekw O.C.T. Compound (Sakura Finetek USA, Inc., Torrance, California), frozen, and sectioned using a cryostat or an American Optical 860 sliding microtome equipped with a freezing stage; sections were mounted individually. Typically, paraffin sections were cut at a thickness of 10–15 µm, plastic sections at 5 µm, and frozen sections at 40 µm. The number of slides per series is a function of the size of the original specimen, section thickness, plane of section, and other factors. Many individual slide series in the Northcutt Collection include more than 100 slides each. Depending on specimen size, from 1 to 50 or more sections may be mounted on a single slide. The Northcutt Collection does not include uncut blocks containing embedded specimens or partially cut blocks used to prepare existing slides.
Most slides were identified originally by an alphanumeric code etched with a diamond scribe into the slide's label region (Fig. 3). Typically, but not always, the code begins with two letters that indicate the Latin name (binomial) of the species. “PM,” for example, is the code for the sea lamprey, Petromyzon marinus. Additional characters indicate the number of the slide series of a given species (e.g., “PM-2” for the second series of P. marinus); multiple slides within a given series are numbered sequentially (1, 2, 3, etc.). When the Northcutt Collection came to the MCZ, each slide series was in addition given a Special Collections (SC) number, and a unique barcode sticker was affixed to each slide to aid tracking its physical location in storage cabinets (Fig. 3). Each SC number corresponds to a unique specimen record in MCZbase that contains all metadata associated with a given slide series, such as specimen preservative, section thickness, staining procedure, developmental stage, specimen size and age, handwritten notes by Prof. Northcutt or other investigators, and, as they are generated, links to slide scan files on Faculty of Arts & Sciences Research Computing-managed network storage (Fig. 4). The name of the preparator is known for several series, and this information too is declared on the corresponding MCZbase record. For example, two whole-embryo series of spiny dogfish, Squalus acanthias, were cut by James DuPrie (Fig. 5), and at least 38 histochemical series of numerous species were cut by Ron Nichols. Finally, many slides are annotated with marks and notations made during original surveys and highlighting sections selected for use in publications. Typically, these annotations were made on the coverslip in alcohol-soluble ink, and every effort has been made to retain these annotations as slides are unpacked, cleaned, imaged, etc.
Figure 3.
Northcutt Collection slide of spiny dogfish, Squalus acanthias (Special Collections 3780, slide 32). A barcode sticker has been affixed to the label region at left, which also has the original Northcutt number, SA-62, etched with a diamond scribe. See also Figure 4.
Figure 4.
MCZbase specimen record of one Northcutt Collection slide series. Special Collections 3780 comprises 48 slides prepared from a 62-mm-long embryo of spiny dogfish, Squalus acanthias (Northcutt number SA-62). When digital whole-slide images are available, as here, thumbnail images are displayed in the media field (left column). Clicking on (Full) below a given thumbnail image opens the full image. See also Figure 3.
Figure 5.
Preparation notes and scanning electron micrograph (SEM) accompanying Special Collections 3762, a series of 99 Northcutt Collection slides of an embryo of spiny dogfish, Squalus acanthias. The notes identify the person who prepared the sections, James J. DuPrie, and provide other important information. SEM by William E. Bemis.
ARRANGEMENT OF SECTIONS
Sections prepared in paraffin embedding media, including Bodian-stained series in the Northcutt Collection, are typically arranged in one or more horizontal rows, each with successive sections in a “left-to-right” numerical sequence that parallels the long axis of the slide (Fig. 6). Sections cut from tissue blocks embedded in plastic are organized instead in a series of vertical columns, each with an “up–down” sequence of sections. For both paraffin and plastic sections, the series begins in the top left corner of the slide, adjacent to the label region, and it ends in the lower right corner. When each successive section is mounted, the “offset distance” (α) between sections is 0 µm. Nonzero values of α apply to situations in which sections to be mounted were saved at regular intervals, e.g., every fifth section.
PUBLICATIONS BASED ON THE NORTHCUTT COLLECTION
Publications by Prof. Northcutt and his many students, postdocs, and professional collaborators are listed in Appendix 1. Nearly all of these publications report studies that were based on examination of slides in the Northcutt Collection. Publications by additional workers who utilized the slides in their research are not included, but as we learn of such works their citations will be added to an online, up-to-date version of this list that will be maintained by the MCZ and linked to Northcutt Collection metadata: https://mcz.harvard.edu/r-glenn-northcuttcollection. Please send information regarding such publications to MCZ_collections_ operations@oeb.harvard.edu. When a given slide series can be associated with a particular publication based on it, we will upload a Portable Document Format (PDF) version of the publication to the corresponding MCZbase specimen record for use by students and researchers.
ANCILLARY MATERIALS
Developmental Series Preserved in Fluid
Associated with the slide collection are several important developmental series preserved in fluid. These include specimens of African knifefish (Gymnarchus niloticus), Australian lungfish (Neoceratodus forsteri), and aquatic and terrestrial caecilians (Typhlonectes compressicauda and Ichthyophis kohtaoensis). Some of these developmental series have already been embedded in plastic and sectioned (e.g., embryos of Neoceratodus and Ichthyophis).
Unpublished Notes and Drawings
Unpublished scanning electron micro-graphs, labeled camera lucida drawings of sections, notes, and schematic diagrams of embryonic materials are associated with several specimens in the Northcutt Collection (Fig. 5). These materials will be digitized and linked with the corresponding online (MCZbase) specimen records for ready access.
NORTHCUTT TAXONOMIC INVENTORY
Slide series in the Northcutt Collection, organized taxonomically by higher taxon, genus, and species, are listed in Table 1. Some species names originally used to identify the slide series (“Northcutt Taxonomy”) are no longer in use; “Current Taxonomy” lists the corresponding valid names obtained from the following sources: World Register of Marine Species (WoRMS Editorial Board, 2024); Eschmeyer's Catalog of Fishes (Fricke et al., 2024); Amphibian Species of the World 6.2 (Frost, 2024); eBird/ Clements Checklist v2023b (Clements et al., 2023); Mammal Diversity Database, v. 1.12.1 (Mammal Diversity Database, 2023); ITIS (Integrated Taxonomic Information System on-line database); National Center for Biotechnology Information (NCBI) Taxonomy (Schoch et al., 2020); and The Reptile Database (Uetz et al., 2023). For a few series identified originally only to genus (or family), the species cannot be determined. A few additional slide series and individual slides not listed in Table 1 include sections of domestic chicken, unidentified mammals and frogs, and human spinal cord and fetal brain. The latter materials will be transferred to an appropriate repository that is authorized to maintain human remains.
Table 1.
Slide series in the Northcutt Collection, organized taxonomically by higher taxon, genus, and species. “Number of Slide Series” indicates the total number of series and, within parentheses, the corresponding numbers of neuroanatomical series/embryological series/histochemical series/flat mounts.
Table 1.
Continued.
Table 1.
Continued.
Table 1.
Continued.
Table 1.
continued.
Table 1.
Continued.
Table 1.
Continued.
Table 1.
Continued.
Examples of slide series in the Northcutt Collection, with associated metadata regarding specimen type, slide preparation, etc., are listed in Table 2. Additional notes regarding specimen source and preservation, section quality, associated publications, and other features are available for many series. They can be obtained from the corresponding online specimen records in MCZbase or by direct communication with curatorial staff.
DISCUSSION
The Northcutt Collection is an irreplaceable resource for studies of the evolution and development of the vertebrate brain and nervous system, especially for the current generation of neuroscientists using molecular and genetic approaches to elucidate mechanisms underlying evolutionary innovations. It complements other existing brain collections whose potential contributions to comparative neuroanatomy are largely unrealized (Iwaniuk, 2010, 2011; Kaas and van Eden 2011; Zilles et al., 2011). It is the product of a unique period in human and scientific history, when the dedication and resources needed to assemble such a collection matched global access to the specimens that are its basis. Changing patterns of science funding, changing national regulations regarding access to diverse biological materials, and, most important, changing and degraded natural environments make it unlikely that such a collection will be replicated in the future. Many of the most important studies based on the Northcutt Collection were made at Scripps Institution of Oceanography, where Prof. Northcutt was a member of the five-faculty Neurobiology Unit. Led by Theodore Bullock, the other members were Walter Heiligenberg, Ad Kalmijn, and James Enright. The Neurobiology Unit became an attractive destination for students, colleagues and visitors from around the world, many of whom contributed to the scientific study of the Northcutt Collection (Appendix 2).
The Northcutt Collection can serve as the basis for many future research projects, ranging from comparative cytoarchitectonic studies to the comparative embryology of placodally derived sense organs and cranial nerves. Cytoarchitectonics was a primary rationale for the main (neuroanatomical) collection, but the full potential of this data set has never been realized because it was assembled sequentially over many years as individual species became available. Now, however, many of the most important vertebrate taxa are well represented, so, at last, they may be compared directly. There are, for example, exquisite but unstudied series of kelp bass (Paralabrax clathratus), Picasso triggerfish (Rhinecanthus aculeatus), and Nile crocodile (Crocodylus niloticus). In addition, several slide series in the histochemical collection include beautiful sections stained with cresyl violet. The thickness of these sections (40 µm) makes them especially useful as reference material for studies of cytoarchitectonics. Similarly, the embryonic collection contains excellent thin plastic sections prepared to examine lateral line and cranial nerve development in shovelnose sturgeon (Scaphirhynchus platorynchus), Australian lungfish (N. forsteri), and the Koa Tao Island caecilian (I. kohtaoensis), but these studies remain to be pursued. The availability of additional fluid-preserved, intact embryos for some of these series will facilitate complementary studies using methods such as scanning electron microscopy and diffusible iodine-based contrast-enhanced computed tomography to visualize sense organs and nerves, respectively.
Now that the Northcutt Collection is accessioned and properly housed in MCZ facilities, attention has shifted to making these valuable materials readily accessible to a variety of audiences. Digital imaging of the slides will undoubtedly facilitate their use in research and education and complement novel technologies for studying brain structure, development, and function (Motta et al., 2019; Kalra et al., 2020; Shapson-Coe et al., 2024). It will foster fruitful collaborations between the neuroscience and biodiversity communities and, together with related projects that seek the mass digitization and sharing of other biological collections, will enhance the ability of natural history institutions to more fully serve both science and society and thus move beyond their traditional constituencies (Suarez and Tsutsui, 2004; Lendemer et al., 2020; Heberling et al., 2021; Blackburn et al., 2024). Two recent grant awards, one from the U.S. National Science Foundation and another from the Harvard Faculty of Arts & Sciences, are making this goal a reality. High-resolution whole-slide images prepared by using high-throughput, automated slide scanners (Fig. 7) are being served online in two ways: directly via individual records in MCZ's museum-wide specimen database, MCZbase; and indirectly via the digital image repository MorphoSource. (All of the whole-slide images are maintained on storage servers at Harvard.) As of 11 December 2024, 8,255 whole-slide images of the Northcutt Collection have been prepared and are available for viewing, analysis, and downloading from both sites. Details regarding the whole-slide imaging workflow and other aspects of image sharing will be presented in a subsequent publication.
ACKNOWLEDGMENTS
Andrew Bass, Sophie Beatrice Cooper, Cory Hahn, Brendan Haley, Jeremy Kisala, Margaret Marchaterre, Joshua Moyer, Samuel Potter, Georg Striedter, Andrew Williston, and Kara Yopak assisted with packing, transporting, unpacking, cleaning, accessioning, and barcoding the Northcutt Collection. The Tontogany Creek Fund and R. Glenn Northcutt defrayed costs associated with moving the collection from University of California San Diego to Cornell. Digitization of the Northcutt Collection is supported by the National Science Foundation (DBI-2122620, to J.H. and Josh Sanes) and by the Harvard University Faculty of Arts & Sciences Dean's Competitive Fund for Promising Scholarship (2020 cycle, to J.H.). Andrew Bass, Michael Pritz, and an anonymous reviewer provided valuable suggestions regarding earlier drafts. Finally, we thank Glenn and Mary Sue Northcutt for the decades they spent preparing, curating, and sharing the R. Glenn Northcutt Collection of Comparative Vertebrate Neuroanatomy and Embryology. By facilitating ready access to the Collection, they enabled students and researchers from all over the world to study these materials, thus transforming the study of comparative vertebrate neurobiology.
LITERATURE CITED
Appendices
APPENDIX 1
Publications by Prof. Northcutt and collaborators; nearly all are based on slides in the Northcutt Collection. Additional publications by other workers who used the slides in their research are not included.
Amemiya, F., and R. G. Northcutt. 1996. Afferent and efferent connections of the central prosencephalic nucleus in the Pacific hagfish. Brain, Behavior and Evolution 47: 149–155.
Bardet, S. M., M. Martinez-de-la-Torre, R. G. Northcutt, J. L. R. Rubenstein, and L. Puelles. 2008. Conserved pattern of OTP-positive cells in the paraventricular nucleus and other hypothalamic sites of tetrapods. Brain Research Bulletin 75: 231–235.
Barlow, L. A., C.-B. Chien, and R. G. Northcutt. 1996. Embryonic taste buds develop in the absence of innervation. Development 122: 1103–1111.
Barlow, L. A., and R. G. Northcutt. 1994. Analysis of the embryonic lineage of vertebrate taste buds. Chemical Senses 19: 715–724.
Barlow, L. A., and R. G. Northcutt. 1995. Embryonic origin of amphibian taste buds. Developmental Biology 169: 273–285.
Barlow, L. A., and R. G. Northcutt. 1997. Taste buds develop autonomously from endoderm without induction by cephalic neural crest or paraxial mesoderm. Development 124: 949–957.
Barlow, L. A., and R. G. Northcutt. 1998. The role of innervation in the development of taste buds: insights from studies of amphibian embryos. Annals of the New York Academy of Sciences 855: 58–69.
Barlow, L. A., and R. G. Northcutt. 1998. Vertebrate taste-bud development: are salamanders the model? Letter to the editor. Trends in Neuroscience 21: 338.
Bass, A. H., M. L. Andry, and R. G. Northcutt. 1983. Visual activity in the telencephalon of the painted turtle, Chrysemys picta. Brain Research 263: 201–210.
Bass, A. H., and R. G. Northcutt. 1981. Primary retinal targets in the Atlantic loggerhead sea turtle, Caretta caretta. Cell and Tissue Research 218: 253–264.
Bass, A. H., and R. G. Northcutt. 1981. Retinal recipient nuclei in the painted turtle, Chrysemys picta: an autoradiographic and HRP study. Journal of Comparative Neurology 199: 97–112.
Bass, A. H., M. B. Pritz, and R. G. Northcutt. 1973. Effects of telencephalic and tectal ablations on visual behavior in the side-necked turtle, Podocnemis unifilis. Brain Research 55: 455–460.
Bemis, W. E., and R. G. Northcutt. 1991. Innervation of the basicranial muscle of Latimeria chalumnae. Environmental Biology of Fishes 32: 147–158.
Bemis, W. E., and R. G. Northcutt. 1992. Skin and blood vessels of the snout of the Australian lungfish, Neoceratodus forsteri, and their significance for interpreting the cosmine of Devonian lungfishes. Acta Zoologica 73: 115–139.
Bemis, W. E., and R. G. Northcutt. 2019. Catalog and Manual for the R. G. Northcutt Collection of Comparative Vertebrate Neuroanatomy and Embryology. Vol. 1.03. Ithaca, New York, and Poway, California.
Bodznick, D., and R. G. Northcutt. 1980. Segregation of electro- and mechanoreceptive inputs to the elasmobranch medulla. Brain Research 195: 313–321.
Bodznick, D., and R. G. Northcutt. 1981. Electroreception in lampreys: evidence that the earliest vertebrates were electroreceptive. Science 212: 465–467.
Bodznick, D., and R. G. Northcutt. 1984. An electrosensory area in the telencephalon of the little skate, Raja erinacea. Brain Research 298: 117–124.
Boord, R. L., and R. G. Northcutt. 1982. Ascending lateral line pathways to the midbrain of the clearnose skate, Raja eglanteria. Journal of Comparative Neurology 207: 274–282.
Boord, R. L., and R. G. Northcutt. 1988. Medullary and mesencephalic pathways and connections of lateral line neurons of the spiny dogfish Squalus acanthias. Brain, Behavior and Evolution 32: 76–88.
Braford, M. R., Jr., and R. G. Northcutt. 1974. Olfactory bulb projections in the bichir, Polypterus. Journal of Comparative Neurology 156: 165–178.
Braford, M. R., Jr., and R. G. Northcutt. 1978. Correlation of telencephalic afferents and SDH distribution in the bony fish Polypterus. Brain Research 152: 157–160.
Braford, M. R., Jr., and R. G. Northcutt. 1983. Organization of the diencephalon and pretectum of the ray-finned fishes, PP. 117–164 IN: R. E. Davis and R. G. Northcutt, editors. Fish Neurobiology. Vol. 2. Ann Arbor: University of Michigan Press.
Braun, C. B., and R. G. Northcutt. 1997. The lateral line system of hagfishes (Craniata: Myxinoidea). Acta Zoologica 78: 247–268.
Braun, C. B., and R. G. Northcutt. 1998. Cutaneous exteroreceptors and their innervation in hagfishes, PP. 510–532 IN: J. M. Jørgensen, J. P. Lomholt, R. E. Weber, and H. Malte, editors. The Biology of Hagfishes. London: Chapman and Hall.
Braun, C. B., and R. G. Northcutt. 1999. Chordate and vertebrate body structure: brain and cranial nerves, PP. 185–192 IN: R. Singer and M. K. Diamond, editors. Encyclopedia of Paleontology. Chicago: Fitzroy Dearborn Publishers.
Braun, C. B., H. Wicht, and R. G. Northcutt. 1995. Distribution of gonadotropin-releasing hormone immunoreactivity in the brain of the Pacific hagfish, Eptatretus stouti (Craniata: Myxinoidea). Journal of Comparative Neurology 353: 464–476.
Bullock, T. H., D. A. Bodznick, and R. G. Northcutt. 1983. The phylogenetic distribution of electroreception: evidence for convergent evolution of a primitive vertebrate sense modality. Brain Research Reviews 6: 25–46.
Bullock, T. H., and R. G. Northcutt. 1982. A new electroreceptive teleost: Xenomystus nigri (Osteoglossiformes: Notopteridae). Journal of Comparative Physiology 148: 345–352.
Bullock, T. H., and R. G. Northcutt. 1984. Nervus terminalis in dogfish (Squalus acanthias, Elasmobranchii) carries tonic efferent impulses. Neuroscience Letters 44: 155–160.
Bullock, T. H., R. G. Northcutt, and D. A. Bodznick 1982. Evolution of electroreception. Trends in Neurosciences 5: 50–53.
Butler, A. B., and R. G. Northcutt. 1971. Ascending tectal efferent projections in the lizard Iguana iguana. Brain Research 35: 597–601.
Butler, A. B., and R. G. Northcutt. 1971. Retinal projections in Iguana iguana and Anolis carolinensis. Brain Research 26: 1–13.
Butler, A. B., and R. G. Northcutt. 1973. Architectonic studies of the diencephalon of Iguana iguana (Linnaeus). Journal of Comparative Neurology 149: 439–462.
Butler, A. B., and R. G. Northcutt. 1978. New thalamic visual nuclei in lizards. Brain Research 149: 469–476.
Butler, A. B., and R. G. Northcutt. 1992. Retinal projections in the bowfin, Amia calva: cytoarchitectonic and experimental analysis. Brain, Behavior and Evolution 39: 169–193.
Butler, A. B., and R. G. Northcutt. 1993. The diencephalon of the Pacific herring, Clupea harengus. I. Cytoarchitectonic analysis. Journal of Comparative Neurology 328: 527–546.
Butler, A. B., M. F. Wullimann, and R. G. Northcutt. 1991. Comparative cytoarchitectonic analysis of some visual pretectal nuclei in teleosts. Brain, Behavior and Evolution 38: 92–114.
Catania, K. C., R. G. Northcutt, and J. H. Kaas. 1999. The development of a biological novelty: a different way to make appendages as revealed in the snout of the star-nosed mole Condylura cristata. Journal of Experimental Biology 202: 2719–2726.
Catania, K. C., R. G. Northcutt, J. H. Kaas, and P. D. Beck. 1993. Nose stars and brain stripes. Nature 364: 493.
Collin, S. P., and R. G. Northcutt. 1993. The visual system of the Florida garfish, Lepisosteus platyrhincus (Ginglymodi). III. Retinal ganglion cells. Brain, Behavior and Evolution 42: 295–320.
Collin, S. P., and R. G. Northcutt. 1995. The visual system of the Florida garfish, Lepisosteus platyrhincus (Ginglymodi). IV. Bilateral projections and the binocular visual field. Brain, Behavior and Evolution 45: 34–53.
Corwin, J. T., and R. G. Northcutt. 1982. Auditory centers in the elasmobranch brain stem: deoxyglucose autoradiography and evoked potential recording. Brain Research 236: 261–273.
Cruce, W. L. R., S. L. Stuesse, and R. G. Northcutt. 1999. Brainstem neurons with descending projections to the spinal cord of two elasmobranch fishes, thornback guitarfish, Platyrhinoidis triseriata, and horn shark, Heterodontus francisci. Journal of Comparative Neurology 403: 534–560.
Davis, R. E., and R. G. Northcutt, editors. 1983. Fish Neurobiology Higher Brain Areas and Functions. Vol. 2. Ann Arbor: University of Michigan Press.
Demski, L. S., and R. G. Northcutt. 1983. The terminal nerve: a new chemosensory system in vertebrates? Science 220: 435–437.
Demski, L. S., and R. G. Northcutt. 1996. The brain and cranial nerves of the white shark: an evolutionary perspective, PP. 121–130 IN: A. P. Klimley and D. G. Ainley, editors. Great White Sharks. The Biology of Carcharodon carcharias. New York: Academic Press.
Ebbesson, S. O. E., and R. G. Northcutt. 1976. Neurology of anamniotic vertebrates, PP. 115–146 IN: R. B. Masterton, M. E. Bitterman, C. B. G. Campbell, and N. Hotton, editors. Evolution of Brain and Behavior in Vertebrates. Hillsdale, New Jersey: Lawrence Erlbaum Associates, Inc.
Eisthen, H. L., and R. G. Northcutt. 1996. Silver lampreys (Ichthyomyzon unicuspis) lack a gonadotropin-releasing hormone- and FMRFamide-immunoreactive terminal nerve. Journal of Comparative Neurology 370: 159–172.
Epperlein, H. H., R. Cerny, and R. G. Northcutt. 2001. Early developmental processes in vertebrates. Annals of Anatomy 183: 581–592.
Fritzsch, B., and R. G. Northcutt. 1992. A plastic embedding technique for analyzing fluorescent dextran-amine labeled neuronal profiles. Biotechnic and Histochemistry 67: 153–157.
Fritzsch, B., and R. G. Northcutt. 1993. Cranial and spinal nerve organization in amphioxus and lampreys: evidence for an ancestral craniate pattern. Acta Anatomica 148: 96–109.
Fritzsch, B., and R. G. Northcutt. 1993. Origin and migration of trochlear, oculomotor and abducent motor neurons in Petromyzon marinus L. Developmental Brain Research 74: 122–126.
Gans, C., and R. G. Northcutt. 1973. Report of a conference on reptilian neuroanatomy. Brain, Behavior and Evolution 7: 248–251.
Gans, C., and R. G. Northcutt. 1983. Neural crest and the origin of vertebrates: a new head. Science 220: 268–274.
Gans, C., and R. G. Northcutt. 1985. Neural crest: the implications for comparative anatomy, PP. 507–514 IN: H.-R. Duncker and G. Fleischer, editors. Functional Morphology in Vertebrates. Stuttgart, Germany: Gustav Fisher.
Gans, C., R. G. Northcutt, and P. S. Ulinski, editors. 1979. Biology of the Reptilia, Neurology A. Vol. 9. London: Academic Press.
Gans, C., R. G. Northcutt, and P. S. Ulinski, editors. 1979. Biology of the Reptilia, Neurology B. Vol. 10. London: Academic Press.
Gibbs, M. A., and R. G. Northcutt. 2004. Retinoic acid repatterns axolotl lateral line receptors. International Journal of Developmental Biology 48: 63–66.
Gibbs, M. A., and R. G. Northcutt. 2004. Development of the lateral line system in the shovelnose sturgeon. Brain, Behavior and Evolution 64: 70–84.
Gillis, J. A., M. S. Modrell, R. G. Northcutt, K. C. Catania, C. A. Luer, and C. V. H. Baker. 2012. Electrosensory ampullary organs are derived from lateral line placodes in cartilaginous fishes. Development 139: 3142–3146.
González, A., R. Morona, J. M. López, N. Moreno, and R. G. Northcutt. 2010. Lungfishes, like tetrapods, possess a vomeronasal system. Frontiers in Neuroanatomy 4, 130: 1–11.
González, A., and R. G. Northcutt. 2009. An immunohistochemical approach to lungfish telencephalic organization. Brain, Behavior and Evolution 74: 43–55.
González, A., and R. G. Northcutt. 2011. Functional morphology of the brains of sarcopterygian fishes: lungfishes and Latimeria, PP. 46–55 IN: A. P. Farrell, editor. The Encyclopedia of Fish Physiology: From Genome to Environment. Vol. 1. San Diego, California: Academic Press.
Heath, J. E., E. Gasdorf, and R. G. Northcutt. 1968. The effect of thermal stimulation of anterior hypothalamus on blood pressure in the turtle. Comparative Biochemical Physiology 26: 509–518.
Heath, J. E., R. G. Northcutt, and R. P. Barber. 1969. Rotational optokinesis in reptiles and its bearing on pupillary shape. Zeitschrift für Vergleichende Physiologie 62: 75–85.
Hoffman, M. H., and R. G. Northcutt. 2008. Organization of major telencephalic pathways in an elasmobranch, the thornback ray Platyrhinoidis triseriata. Brain, Behavior and Evolution 72: 307–325.
Hofmann, M. H., and R. G. Northcutt. 2012. Forebrain organization in elasmobranchs. Brain, Behavior and Evolution 80: 142–151.
Holmes, P. H., and R. G. Northcutt. 2003. Connections of the pallial telencephalon in the Senegal bichir, Polypterus. Brain, Behavior and Evolution 61: 113–147.
Khonsari, R. H., B. Li, P. Vernier, R. G. Northcutt, and P. Janvier. 2009. Agnathan brain anatomy and craniate phylogeny. Acta Zoologica (Stockholm) 90 (Suppl. 1): 52–68.
Kicliter, E. E., and R. G. Northcutt. 1975. Ascending afferents to the telencephalon of ranid frogs: an anterograde degeneration study. Journal of Comparative Neurology 161: 239–254.
Kokoros, J. J., and R. G. Northcutt. 1977. Telencephalic efferents of the tiger salamander Ambystoma tigrinum tigrinum (Green). Journal of Comparative Neurology 173: 613–628.
Krug, L., H. Wicht, and R. G. Northcutt. 1993. Afferent and efferent connections of the thalamic eminence in the axolotl, Ambystoma mexicanum. Neuroscience Letters 149: 145–148.
Landreth, G. E., E. A. Neale, J. H. Neale, R. S. Duff, M. R. Braford, Jr., R. G. Northcutt, and B. W. Agranoff. 1975. Evaluation of (3H)-proline for radioautographic tracing of axonal projections in the teleost visual system. Brain Research 91: 25–42.
López, J. M., L. Domínguez, R. Morona, R. G. Northcutt, and A. González. 2012. Organization of the cholinergic systems in the brain of two lungfishes, Protopterus dolloi and Neoceratodus forsteri. Brain Structure and Function 217: 549–576.
López, J. M., J. Perlado, R. Morona, R. G. Northcutt, and A. González 2013 Neuroanatomical organization of the cholinergic system in the brain of a basal actinopterygian fish, the Senegal bichir Polypterus senegalus. Journal of Comparative Neurology 521: 24–49.
Metscher, B. D., R. G. Northcutt, D. M. Gardiner, and S. V. Bryant. 1997. Homeobox genes in axolotl lateral line placodes and neuromasts. Development, Genes and Evolution 207: 287–295.
Modrell, M. S., W. E. Bemis, R. G. Northcutt, M. C. Davis, and C. V. H. Baker. 2011. Electrosensory ampullary organs are derived from lateral line placodes in bony fishes. Nature Communications 2: 496.
Morona, R., J. M. López, R. G. Northcutt, and A. González. 2013. Comparative analysis of the organization of the cholinergic system in the brains of two holostean fishes, the Florida gar Lepisosteus platyrhincus and the bowfin Amia calva. Brain, Behavior and Evolution 81: 109–142.
Morona, R., J. M. López, R. G. Northcutt, and A. González. 2013. Regional chemoarchitecture of the brain of lungfishes based on calbindin D-28K and calretinin immunohistochemistry Journal of Comparative Neurology 526: 1457–1497.
Morona, R., R. G. Northcutt, and A. González. 2010. Immunohistochemical localization of calbindinD28k and calretinin in the spinal cord of lungfishes. Brain, Behavior and Evolution 76: 198–210.
Morona, R., R. G. Northcutt, and A. González. 2011. Immunohistochemical localization of calbindinD28k and calretinin in the retina of two lungfishes, Protopterus dolloi and Neoceratodus forsteri: colocalization with choline acetyltransferase and tyrosine hydroxylase. Brain Research 1368: 28–43.
Neary, T. J., and R. G. Northcutt. 1983. Nuclear organization of the bullfrog diencephalon. Journal of Comparative Neurology 213: 262–278.
New, J. G., and R. G. Northcutt. 1984. Central projections of the lateral line nerves in the shovelnose sturgeon. Journal of Comparative Neurology 225: 129–140.
New, J. G., and R. G. Northcutt. 1984. Primary projections of the trigeminal nerve in two species of sturgeon: Acipenser oxyrhynchus and Scaphirhynchus platorynchus. Journal of Morphology 182: 125–136.
Northcutt, R. G. 1966. Analysis of reptilian cortical structures. Nature 210: 848–850.
Northcutt, R. G. 1967. Architectonic studies of the telencephalon of Iguana iguana. Journal of Comparative Neurology 130: 109–148.
Northcutt, R. G. 1969. Discussion of the preceding paper. Annals of the New York Academy of Sciences 167: 180–185.
Northcutt, R. G. 1970. [Review of] D. G. Senn, Bau und Ontogenese von Zwischen-Und Mittelhirn Bei Lacerta sicula (Rafinesque), S. Karger, Basel, 1968. Copeia 1970: 396.
Northcutt, R. G. 1970. The Telencephalon of the Western Painted Turtle (Chrysemys picta belli). Illinois Biological Monograph. Urbana: University of Illinois Press.
Northcutt, R. G. 1971. Comparative morphology of the vertebrate brain and spinal cord, PP. 62–67 IN: McGraw-Hill Encyclopedia of Science and Technology,.
Northcutt, R. G. 1973. [Review of] C. R. Noback and W. Montagna, editors The Primate Brain (Advances in Primatology, Vol. 1). New York: Appleton-Century-Crofts, 1970. American Journal of Physical Anthropology 39: 482–485.
Northcutt, R. G. 1974. [Review of] H. B. Sarnat and M. G. Netsky, Evolution of the Nervous System. New York: Oxford University Press, 1974. Brain, Behavior and Evolution 10: 471–472.
Northcutt, R. G. 1974. Some histochemical observations on the telencephalon of the bullfrog, Rana catesbeiana Shaw. Journal of Comparative Neurology 157: 379–390.
Northcutt, R. G. 1976. [Review of] M. Ali, editor, Vision in Fishes: New Approaches in Research (Papers from a NATO Advanced Study Institute), New York: Plenum Press, 1976. Science 193: 225–226.
Northcutt, R. G., editor. 1977. Recent advances in the biology of sharks (Proceedings of a Symposium). American Zoologist 17: 289–515.
Northcutt, R. G. 1977. Elasmobranch central nervous system organization and its possible evolutionary significance. American Zoologist 17: 411–429.
Northcutt, R. G. 1977. Retinofugal projections in the lepidosirenid lungfishes. Journal of Comparative Neurology 174: 553–574.
Northcutt, R. G. 1978. Brain organization in the cartilaginous fishes, PP. 117–193 IN: E. S. Hodgson and R. F. Mathewson, editors. Sensory Biology of Sharks, Skates, and Rays. Arlington, Virginia: Office of Naval Research, Department of the Navy.
Northcutt, R. G. 1978. Forebrain and midbrain organization in lizards and its phylogenetic significance, PP. 11–64 IN: N. Greenberg and P. D. MacLean, editors. Behavior and Neurology of Lizards. Rockville, Maryland: U.S. Department of Health, Education & Welfare, NIMH.
Northcutt, R. G. 1979. Central projections of the eighth cranial nerve in lampreys. Brain Research 167: 163–167.
Northcutt, R. G. 1979. Experimental determination of the primary trigeminal projections in lampreys. Brain Research 163: 323–327.
Northcutt, R. G. 1979. Retinofugal pathways in fetal and adult spiny dogfish, Squalus acanthias. Brain Research 162: 219–230.
Northcutt, R. G. 1979. The comparative anatomy of the nervous system and sense organs, PP. 615–769 IN: M. Wake, editor. Hyman's Comparative Vertebrate Anatomy. University of Chicago Press, Chicago.
Northcutt, R. G. 1980. Anatomical evidence of electroreception in the coelacanth (Latimeria chalumnae). Anatomia Histologia Embryologia 9: 289–295.
Northcutt, R. G. 1980. Central auditory pathways in anamniotic vertebrates, PP. 79–118 IN: A. N. Popper and R. R. Fay, editors. Comparative Studies of Hearing in Vertebrates). Springer-Verlag, New York.
Northcutt, R. G. 1980. Retinal projections in the Australian lungfish. Brain Research 185: 85–90.
Northcutt, R. G. 1981. Audition and the central nervous system of fishes, PP. 331–355 IN: W. N. Tavolga, A. N. Popper and R. R. Fay, editors. Hearing and Sound Communication in Fishes. New York: Springer-Verlag.
Northcutt, R. G. 1981. Evolution of the telencephalon in nonmammals. Annual Review of Neuroscience 4: 301–350.
Northcutt, R. G. 1981. Localization of neurons afferent to the telencephalon in a primitive bony fish, Polypterus palmas. Neuroscience Letters 22: 219–222.
Northcutt, R. G. 1982. Localization of neurons afferent to the optic tectum in longnose gars. Journal of Comparative Neurology 204: 325–335.
Northcutt, R. G. 1983. [Review of] H. B. Sarnat and M. G. Netsky, Evolution of the Nervous System, 2nd ed. New York: Oxford University Press, 1981. Trends in Neurosciences 6: 474–475.
Northcutt, R. G. 1983. [Review of] W. J. A. J. Smeets, R. Nieuwenhuys and B. L. Roberts, The Central Nervous System of Cartilaginous Fishes. New York: Springer-Verlag, 1983. Science 222: 156.
Northcutt, R. G. 1983. Evolution of the optic tectum in ray-finned fishes, pp. 1–42 IN: R. E. Davis and R. G. Northcutt, editors. Fish Neurobiology, Vol. 2. Ann Arbor: University of Michigan Press.
Northcutt, R. G. 1984. [Review of] E. C. Crosby and H. N. Schnitzlein, editors, Comparative Correlative Neuroanatomy of the Vertebrate Telencephalon. New York: MacMillan Publishing, 1982. Bioscience 34: 264.
Northcutt, R. G. 1984. Anatomical organization of the optic tectum in reptiles, PP. 547–600 IN: H. Vanegas, editor. Comparative Neurology of the Optic Tectum. New York: Plenum.
Northcutt, R. G. 1984. Evolution of the vertebrate central nervous system: patterns and processes. American Zoologist 24: 701–716.
Northcutt, R. G. 1984. Parcellation: the resurrection of Hartsoeker and Haeckel. Behavioral and Brain Sciences 7: 345.
Northcutt, R. G. 1985. Brain phylogeny: speculations on pattern and cause, PP. 351–378 IN: M. J. Cohen and F. Strumwasser, editors. Comparative Neurobiology: Modes of Communication in the Nervous System. New York: Wiley.
Northcutt, R. G. 1985. Central nervous system phylogeny: evaluation of hypotheses, PP. 497–505 IN: H.-R. Duncker and G. Fleischer, editors. Functional Morphology in Vertebrates. Stuttgart, Germany: Gustav Fischer.
Northcutt, R. G. 1985. The brain and sense organs of the earliest vertebrates: reconstruction of a morphotype, PP. 81–112 IN: R. E. Foreman, A. Gorbman, J. M. Dodd, and R. Olsson, editors. Evolutionary Biology of Primitive Fishes. New York: Plenum.
Northcutt, R. G. 1986. Electroreception in nonteleost bony fishes, PP. 257–285 IN: T. H. Bullock and W. F. Heiligenberg, editors. Electroreception. New York: John Wiley and Sons.
Northcutt, R. G. 1986. Evolution of the octavolateralis system: evaluation and heuristic value of phylogenetic hypotheses, PP. 3–14 IN: R. W. Ruben, T. R. Van De Water, and E. W. Rubel, editors. The Biology of Change in Otolaryngology. New York: Elsevier.
Northcutt, R. G. 1986. Strategies of comparison: how do we study brain evolution? Verhandlungen der Deutschen Zoologischen Gesellschaft 79: 91–104.
Northcutt, R. G. 1987. Evolution of the vertebrate brain, PP. 415–418 IN: G. Adelman, editor. Encyclopedia of Neuroscience. Boston: Birkhauser.
Northcutt, R. G. 1987. Lungfish neural characters and their bearing on sarcopterygian phylogeny. Journal of Morphology 190(Suppl. 1): 277–297.
Northcutt, R. G. 1988. Sensory and other neural traits and the adaptationist program: mackerels of San Marco?, PP. 869–883 IN: J. Atema, R. R. Fay, A. N. Popper, and W. N. Tavolga, editors. Sensory Biology of Aquatic Animals. New York: Springer-Verlag.
Northcutt, R. G. 1989. Brain variation and phylogenetic trends in elasmobranch fishes. Journal of Experimental Zoology 252(Suppl. 2): 83–100.
Northcutt, R. G. 1989. The phylogenetic distribution and innervation of craniate mechanoreceptive lateral lines, PP. 17–78 IN: S. Coombs, P. Görner, and H. Münz, editors. Mechanosensory Lateral Line: Neurobiology and Evolution. New York: Springer-Verlag.
Northcutt, R. G. 1990. Ontogeny and phylogeny: a reevaluation of conceptual relationships and some applications. Brain, Behavior and Evolution 36: 116–140.
Northcutt, R. G. 1990. The lateral line system of the axolotl. Axolotl Newsletter 19: 5–14.
Northcutt, R. G. 1991. Visual pathways in elasmobranchs: organization and phylogenetic implications. Journal of Experimental Zoology 5: 97–107.
Northcutt, R. G. 1992. Distribution and innervation of lateral line organs in the axolotl. Journal of Comparative Neurology 325: 95–123.
Northcutt, R. G. 1992. The phylogeny of octavolateralis ontogenies: a reaffirmation of Garstang's phylogenetic hypothesis, PP. 21–47 IN: D. B. Webster, R. R. Fay, and A. N. Popper, editors. The Evolutionary Biology of Hearing. New York: Springer-Verlag.
Northcutt, R. G. 1993. A reassessment of Goodrich's model of cranial nerve phylogeny. Acta Anatomica 148: 71–80.
Northcutt, R. G. 1993. The primitive pattern of development of lateral line organs. Journal of Comparative Physiology A 173: 717–718.
Northcutt, R. G. 1995. The forebrain of gnathostomes: in search of a morphotype. Brain, Behavior and Evolution 46: 275–318.
Northcutt, R. G. 1996. [Review of] H. Gee, Before the Backbone. Views on the Origin of the Vertebrates. New York: Chapman and Hall, 1996. Science 274: 1629.
Northcutt, R. G. 1996. The agnathan ark: the origin of craniate brains. Brain, Behavior and Evolution 48: 237–247.
Northcutt, R. G. 1996. The origin of craniates: neural crest, neurogenic placodes and homeobox genes. Israel Journal of Zoology 42: S273–S313.
Northcutt, R. G. 1997. Evolution of gnathostome lateral line ontogenies. Brain, Behavior and Evolution 50: 25–37.
Northcutt, R. G. 1997. Evolution of vertebrate brains. IN: G. Adelman and B. H. Smith, editors. Encyclopedia of Neuroscience, 2nd ed. CD-ROM version. Amsterdam: Elsevier Science.
Northcutt, R. G. 1997. Swimming against the current. Nature 389: 915–916.
Northcutt, R. G. 1998. [Review of] R. Nieuwenhuys, H. J. den Donkelaar and C. Nicholson, The Central Nervous System of Vertebrates. New York: Springer, 1997. Nature 392: 670–671.
Northcutt, R. G. 1999. [Review of] B. K. Hall and M. H. Wake, editors, The Origin and Evolution of Larval Forms. San Diego, California: Academic Press, 1999. Cell 98: 696–697.
Northcutt, R. G. 1999. Evolution of vertebrate brains, PP. 688–692 IN: G. Adelman and B. H. Smith, editors. Elsevier's Encyclopedia of Neuroscience, 2nd ed. Amsterdam: Elsevier Science B. V.
Northcutt, R. G. 1999. Field homology: a meaningless concept. European Journal of Morphology 37: 95–99.
Northcutt, R. G. 1999. Sensory structures in vertebrates: lateral line system, PP. 650–657 IN: R. Singer and M. K. Diamond, editors. Encyclopedia of Paleontology. Chicago: Fitzroy Dearborn Publishers.
Northcutt, R. G. 2001. [Review of] P. E. Ahlberg, editor, Major Events in Early Vertebrate Evolution. London: Taylor and Frances, 2001. Palaeontology Newsletter 47: 93–99.
Northcutt, R. G. 2001. Changing views of brain evolution. Brain Research Bulletin 55: 663–674.
Northcutt, R. G. 2001. Lancelet lessons: evaluating a phylogenetic model. Journal of Comparative Neurology 435: 391–393.
Northcutt, R. G. 2002. Understanding vertebrate brain evolution. Integrative and Comparative Biology 42: 743–756.
Northcutt, R. G. 2003. Development of the lateral line system in the channel catfish, PP. 137–159 IN: H. I. Browman and A. B. Skiftesvik, editors. The Big Fish Bang (Proceedings of the 26th Annual Larval Fish Conference). Bergen, Norway: Institute of Marine Research.
Northcutt, R. G. 2003. Origin of the isthmus? A comparison of the brains of lancelets and vertebrates. Journal of Comparative Neurology 466: 316–318.
Northcutt, R. G. 2003. The use and abuse of developmental data—commentary on Aboitiz, Morales, and Montiel. Brain and Behavioral Sciences 26: 565–566.
Northcutt, R. G. 2004. Taste buds: development and evolution. Brain, Behavior and Evolution 64: 198–206.
Northcutt, R. G. 2005. Ontogeny of electroreceptors and their neural circuitry, PP. 112–131 IN: T. H. Bullock, C. D. Hopkins, A. N. Popper, and R. R. Fay, editors. Electroreception. New York: Springer.
Northcutt, R. G. 2005. Taste bud development in the channel catfish. Journal of Comparative Neurology 482: 1–16.
Northcutt, R. G. 2005. The new head hypothesis revisited. Journal of Experimental Zoology 304B: 274–297.
Northcutt, R. G. 2006. Connections of the lateral and medial divisions of the goldfish telencephalic pallium. Journal of Comparative Neurology 494: 903–943.
Northcutt, R. G. 2008. Forebrain evolution in bony fishes. Brain Research Bulletin 75: 191–205.
Northcutt, R. G. 2008. Historical hypotheses regarding vertebrate head segmentation. Integrative and Comparative Biology 48: 611–619.
Northcutt, R. G. 2009. Telencephalic organization in the spotted African lungfish, Protopterus dolloi: A new cytological model. Brain, Behavior and Evolution 73: 59–80.
Northcutt, R. G. 2009. The phylogeny of nucleus medianus of the posterior tubercle in ray-finned fishes. Journal of Integrative Zoology 4: 134–152.
Northcutt, R. G. 2010. Cladistic analysis reveals brainless Urbilateria. Brain, Behavior and Evolution 76: 1–2.
Northcutt, R. G. 2011. Do teleost fishes possess a homologue of mammalian isocortex? Brain, Behavior and Evolution 78: 136–138.
Northcutt, R. G. 2011. Evolving large and complex brains. Science 332: 926–927.
Northcutt, R. G. 2011. Olfactory projections in the white sturgeon, Acipenser transmontanus: an experimental study. Journal of Comparative Neurology 519: 1999–2022.
Northcutt, R. G. 2011. The central nervous system of lungfishes, PP. 393–446 IN: J. M. Jørgensen and J. Joss, editors. Biology of Lungfishes. Enfield, New Hampshire: Science Publishers.
Northcutt, R. G. 2012. Evolution of centralized nervous systems: two schools of evolutionary thought. Proceedings of the National Academy of Sciences of the United States of America 109(Suppl. 1): 10626–10633.
Northcutt, R. G. 2013. Variation in reptilian brains and cognition. Brain, Behavior and Evolution 82: 45–54.
Northcutt, R. G., and L. A. Barlow. 1998. Amphibians provide new insights into taste-bud development. Trends in Neurosciences 21: 38–43.
Northcutt, R. G., L. A. Barlow, C. B. Braun, and K. C. Catania. 2000. Distribution and innervation of taste buds in the axolotl. Brain, Behavior and Evolution 56: 123–145.
Northcutt, R. G., and W. E. Bemis. 1993. Cranial nerves of the coelacanth, Latimeria chalumnae [Osteichthyes: Sarcopterygii: Actinistia], and comparisons with other Craniata. Brain, Behavior and Evolution 42(Suppl. 1): 1–76.
Northcutt, R. G., and H. Bleckmann. 1993. Pit organs in axolotls: a second class of lateral line neuromasts. Journal of Comparative Physiology A 172: 439–446.
Northcutt, R. G., and D. A. Bodznick. 1983. Areas of electrosensory activity in the mesencephalon of the spiny dogfish, Squalus acanthias. Bulletin (Mount Desert Island Biological Laboratory) 23: 33–36.
Northcutt, R. G., and M. R. Braford, Jr. 1980. New observations on the organization and evolution of the telencephalon of actinopterygian fishes, PP. 41–98 IN: S. O. E. Ebbesson, editor. Comparative Neurology of the Telencephalon. New York: Plenum Press.
Northcutt, R. G., and M. R. Braford, Jr. 1984. Some efferent connections of the superficial pretectum in the goldfish. Brain Research 296: 181–184.
Northcutt, R. G., and K. Brändle. 1995. Development of branchiomeric and lateral line nerves in the axolotl. Journal of Comparative Neurology 355: 427–454.
Northcutt, R. G., K. Brändle, and B. Fritzsch. 1995. Electroreceptors and mechanosensory lateral line organs arise from single placodes in axolotls. Developmental Biology 168: 358–373.
Northcutt, R. G., and A. B. Butler. 1974. Evolution of reptilian visual systems: retinal projections in a nocturnal lizard, Gekko gecko (Linnaeus). Journal of Comparative Neurology 157: 453–466.
Northcutt, R. G., and A. B. Butler. 1974. Retinal projections in the northern water snake Natrix sipedon sipedon (L.). Journal of Morphology 142: 117–136.
Northcutt, R. G., and A. B. Butler. 1976. Retinofugal pathways in the longnose gar Lepisosteus osseus (Linnaeus). Journal of Comparative Neurology 166: 1–16.
Northcutt, R. G., and A. B. Butler. 1980. Projections of the optic tectum in the longnose gar, Lepisosteus osseus. Brain Research 190: 333–346.
Northcutt, R. G., and A. B. Butler. 1991. Retinofugal and retinopetal projections in the green sunfish Lepomis cyanellus. Brain, Behavior and Evolution 37: 333–354.
Northcutt, R. G., and A. B. Butler. 1993. The diencephalon and optic tectum of the longnose gar, Lepisosteus osseus (L.): cytoarchitectonics and distribution of acetylcholinesterase. Brain, Behavior and Evolution 41: 57–81.
Northcutt, R. G., and A. B. Butler. 1993. The diencephalon of the Pacific herring, Clupea harengus: retinofugal projections to the diencephalon and optic tectum. Journal of Comparative Neurology 328: 547–561.
Northcutt, R. G., K. C. Catania, and B. B. Criley. 1994. Development of lateral line organs in the axolotl. Journal of Comparative Neurology 340: 480–514.
Northcutt, R. G., and R. E. Davis, editors. 1983. Fish Neurobiology, Vol. 1: Brain Stem and Sense Organs. Ann Arbor: University of Michigan Press.
Northcutt, R. G., and R. E. Davis 1983. Telencephalic organization in ray-finned fishes, PP. 203–236 IN: R. E. Davis and R. G. Northcutt, editors. Fish Neurobiology, Vol. 2. Ann Arbor: University of Michigan Press.
Northcutt, R. G., and C. Gans. 1977. [Review of] R. Llinas and W. Precht, editors. Frog Neurobiology. New York: Springer-Verlag, 1976. Quarterly Review of Biology 52: 450.
Northcutt, R. G., and C. Gans. 1983. The genesis of neural crest and epidermal placodes: a reinterpretation of vertebrate origins. Quarterly Review of Biology 58: 1–28.
Northcutt, R. G., and C. Gans. 1985. Vertebrata, PP. 452–455 IN: McGraw-Hill Yearbook of Science and Technology, 1985. New York: McGraw-Hill.
Northcutt, R. G., and A. González. 2011. A reinterpretation of the cytoarchitectonics of the telencephalon of the Comoron coelacanth. Frontiers in Neuroanatomy 5, 9: 1–7.
Northcutt, R. G., and J. E. Heath. 1971. Performance of caimans in a T-maze. Copeia 1971: 557–560.
Northcutt, R. G., and J. E. Heath. 1973. T-maze behavior of the tuatara (Sphenodon punctatus). Copeia 1973: 617–620.
Northcutt, R. G., P. H. Holmes, and J. S. Albert. 2000. Distribution and innervation of lateral line organs in the channel catfish. Journal of Comparative Neurology 421: 570–592.
Northcutt, R. G., and J. H. Kaas. 1995. The emergence and evolution of mammalian neocortex. Trends in Neurosciences 18: 373–379.
Northcutt, R. G., and J. H. Kaas. 1996. Levels of organization and the evolution of isocortex: letter to the editor. Trends in Neurosciences 19: 91–92.
Northcutt, R. G., and E. E. Kicliter. 1980. Organization of the amphibian telencephalon, PP. 203–255 IN: S. O. E. Ebbesson, editor Comparative Neurology of the Telencephalon. New York: Plenum Press.
Northcutt, R. G., and L. E. Muske. 1994. Multiple embryonic origins of gonadotropin-releasing hormone (GnRH) immunoreactive neurons. Developmental Brain Research 78: 279–290.
Northcutt, R. G., T. J. Neary, and D. G. Senn. 1978. Observations on the brain of the coelacanth, Latimeria chalumnae: external anatomy and quantitative analysis. Journal of Morphology 155: 181–192.
Northcutt, R. G., and M. S. Northcutt, editors. 2004. The development of vertebrate sense organs. Proceedings of the 15th Annual Karger Workshop. Brain, Behavior and Evolution 64: 125–206.
Northcutt, R. G., and W. Plassmann. 1989. Electrosensory activity in the telencephalon of the axolotl. Neuroscience Letters 99: 79–84.
Northcutt, R. G., W. Plassmann, P. H. Holmes, and W. M. Saidel. 2004. A pallial visual area in the telencephalon of the bony fish Polypterus. Brain, Behavior and Evolution 64: 1–10.
Northcutt, R. G., and R. L. Puzdrowski. 1988. Projections of the olfactory bulb and nervus terminalis in the silver lamprey. Brain, Behavior and Evolution 32: 96–107.
Northcutt, R. G., A. J. Reiner, and H. J. Karten. 1988. Immunohistochemical study of the telencephalon of the spiny dogfish, Squalus acanthias. Journal of Comparative Neurology 277: 250–267.
Northcutt, R. G., and E. Rink. 2012. Olfactory projections in the lepidosirenid lungfishes. Brain, Behavior and Evolution 79: 4–25.
Northcutt, R. G., and M. C. Ronan. 1992. Afferent and efferent connections of the bullfrog medial pallium. Brain, Behavior and Evolution 40: 1–16.
Northcutt, R. G., and G. J. Royce. 1975. Olfactory bulb projections in the bullfrog Rana catesbeiana. Journal of Morphology 145: 251–268.
Northcutt, R. G., and J. C. Wathey. 1980. Guitarfish possess ipsilateral as well as contralateral retinofugal projections. Neuroscience Letters 20: 237–242.
Northcutt, R. G., and G. Westhoff. 2011. Connections of the medial telencephalic wall in the spotted African lungfish. Brain, Behavior and Evolution 77: 14–32.
Northcutt, R. G., and H. Wicht. 1997. Afferent and efferent connections of the lateral and medial pallia of the silver lamprey. Brain, Behavior and Evolution 49: 1–19.
Northcutt, R. G., K. L. Williams, and R. P. Barber. 1964. Atlas of the Sheep Brain. Urbana, Illinois: Stipes Publishing Co.
Northcutt, R. G., K. L. Williams, and R. P. Barber. 1966. Atlas of the Sheep Brain, 2nd ed. Urbana, Illinois: Stipes Publishing Co.
Northcutt, R. G., and M. F. Wullimann. 1988. The visual system in teleost fishes: morphological patterns and trends, PP. 515–552 IN: J. Atema, R. R. Fay, A. N. Popper, and W. N. Tavolga, editors. Sensory Biology of Aquatic Animals. New York: Springer-Verlag.
Northcutt, R. G., M. F. Wullimann, and M. S. Northcutt, editors. 2009. Forebrain evolution in fishes. Proceedings of the 20th Annual Karger Workshop. Brain, Behavior and Evolution 74: 1–86.
Oelschläger, H. A., C. Helpert, and R. G. Northcutt. 1994. Molluscan cardioexcitatory neuropeptide (FMRFamide) immunochemistry in the nervus terminalis and central nervous system of the bat Eptesicus fuscus. Advances in the Biosciences 93: 173–177.
Oelschläger, H. A., C. Helpert, and R. G. Northcutt. 1998. Coexistence of FMRFamide-like and LHRH-like immunoreactivity in the terminal nerve and forebrain of the big brown bat Eptesicus fuscus. Brain, Behavior and Evolution 52: 139–147.
Oelschläger, H. A., and R. G. Northcutt. 1992. Immunocytochemical localization of luteinizing hormone-releasing hormone (LHRH) in the nervus terminalis and brain of the big brown bat, Eptesicus fuscus. Journal of Comparative Neurology 315: 344–363.
Parent, A., L. Dubé, M. R. Braford, Jr., and R. G. Northcutt. 1978. The organization of monoaminecontaining neurons in the brain of the sunfish (Lepomis gibbosus) as revealed by fluorescence microscopy. Journal of Comparative Neurology 182: 495–516.
Parent, A., and R. G. Northcutt. 1982. The monoaminecontaining neurons in the brain of the garfish, Lepisosteus osseus. Brain Research Bulletin 9: 189–204.
Piñuela, C., and R. G. Northcutt. 2007. Immunohistochemical organization of the forebrain in the white sturgeon, Acipenser transmontanus. Brain, Behavior and Evolution 69: 229–253.
Piotrowski, T., and R. G. Northcutt. 1996. The cranial nerves of the Senegal bichir, Polypterus senegalus (Osteichthyes: Actinopterygii: Cladistia). Brain, Behavior and Evolution 47: 55–102.
Popper, A. N., and R. G. Northcutt. 1983. Structure and innervation of the inner ear of the bowfin, Amia calva. Journal of Comparative Neurology 213: 279–286.
Pritz, M. B., A. H. Bass, and R. G. Northcutt. 1973. A simple apparatus and training techniques for teaching turtles to perform a visual discrimination task. Copeia 1973: 181–183.
Pritz, M. B., W. R. Mead, and R. G. Northcutt. 1970. The effects of Wulst lesions on color, brightness and pattern discrimination in pigeons (Columba livia). Journal of Comparative Neurology 140: 81–100.
Pritz, M. B., and R. G. Northcutt. 1977. Succinate dehydrogenase activity in the telencephalon of crocodiles correlates with the projection areas of sensory thalamic nuclei. Brain Research 124: 357–360.
Pritz, M. B., and R. G. Northcutt. 1980. Anatomical evidence for an ascending somatosensory pathway to the telencephalon in crocodiles, Caiman crocodilus. Experimental Brain Research 40: 342–345.
Puzdrowski, R. L., and R. G. Northcutt. 1989. Central projections of the pineal complex in the silver lamprey, Ichthyomyzon unicuspis. Cell and Tissue Research 225: 269–274.
Reiner, A. J., and R. G. Northcutt. 1987. An immunohistochemical study of the telencephalon of the African lungfish, Protopterus annectens. Journal of Comparative Neurology 256: 463–481.
Reiner, A. J., and R. G. Northcutt. 1992. An immunohistochemical study of the telencephalon of the Senegal bichir Polypterus senegalus. Journal of Comparative Neurology 319: 359–386.
Reiner, A., and R. G. Northcutt. 2000. Succinic dehydrogenase histochemistry reveals the location of the putative primary visual and auditory areas within the dorsal ventricular ridge of Sphenodon punctatus. Brain, Behavior and Evolution 55: 26–36.
Ronan, M., and R. G. Northcutt. 1987. Primary projections of the lateral line nerves in adult lampreys. Brain, Behavior and Evolution 30: 62–81.
Ronan, M. C., and R. G. Northcutt. 1985. The origin of descending spinal projections in lepidosirenid lungfishes. Journal of Comparative Neurology 241: 435–444.
Ronan, M. C., and R. G. Northcutt. 1990. Projections ascending from the spinal cord to the brain in petromyzontid and myxinoid agnathans. Journal of Comparative Neurology 291: 491–508.
Ronan, M. C., and R. G. Northcutt. 1998. The central nervous system of hagfishes, PP. 452–479 IN: J. M. Jørgensen, J. P. Lomholt, R. E. Weber, and H. Malte, editors. The Biology of Hagfishes. London: Chapman and Hall.
Rupp, B., and R. G. Northcutt. 1998. The diencephalon and pretectum of the white sturgeon (Acipenser transmontanus): A cytoarchitectonic study. Brain, Behavior and Evolution 51: 239–262.
Schlosser, G., C. Kintner, and R. G. Northcutt. 1999. Loss of ectodermal competence for lateral line placode formation in the direct developing frog Eleutherodactylus coqui. Developmental Biology 213: 354–369.
Schlosser, G., and R. G. Northcutt. 2000. Development of neurogenic placodes in Xenopus laevis. Journal of Comparative Neurology 418: 121–146.
Schlosser, G., and R. G. Northcutt. 2001. Lateral line placodes are induced during neurulation in the axolotl. Developmental Biology 234: 55–71.
Senn, D. G., and R. G. Northcutt. 1973. The forebrain and midbrain of some squamates and their bearing on the origin of snakes. Journal of Morphology 140: 135–152.
Smeets, W. J. A. J., and R. G. Northcutt. 1987. At least one thalamotelencephalic pathway in cartilaginous fishes projects to the medial pallium. Neuroscience Letters 78: 277–282.
Song, J., and R. G. Northcutt. 1991. Morphology, distribution, and innervation of the lateral-line receptors of the Florida gar, Lepisosteus platyrhincus. Brain, Behavior and Evolution 37: 10–37.
Song, J., and R. G. Northcutt. 1991. The primary projections of the lateral-line nerves of the Florida gar, Lepisosteus platyrhincus. Brain, Behavior and Evolution 37: 38–63.
Striedter, G. F., and R. G. Northcutt. 1989. Two distinct visual pathways through the superficial pretectum in a percomorph teleost. Journal of Comparative Neurology 283: 342–354.
Striedter, G. F., and R. G. Northcutt. 1991. Biological hierarchies and the concept of homology. Brain, Behavior and Evolution 38: 177–189.
Striedter, G. F., and R. G. Northcutt. 2006. Head size constrains forebrain development and evolution in ray-finned fishes. Evolution & Development 8: 215–222.
Striedter, G. F., and R. G. Northcutt. 2020. Brains Through Time: A Natural History of Vertebrates. Oxford, U.K.: Oxford University Press.
Striedter, G. F., and R. G. Northcutt. 2021. The independent evolution of dorsal pallia in multiple vertebrate lineages. Brain, Behavior and Evolution 96: 200–211.
Stuesse, S. L., W. L. R. Cruce, and R. G. Northcutt. 1990. Distribution of tyrosine hydroxylase and serotonin immunoreactive cells in the central nervous system of the thornback guitarfish, Platyrhinoidis triseriata. Journal of Chemical Neuroanatomy 3: 45–58.
Stuesse, S. L., W. L. R. Cruce, and R. G. Northcutt. 1991. Localization of serotonin, tyrosine hydroxylase, and leu-enkephalin immunoreactive cells in the brain stem of the horn shark, Heterodontus francisci. Journal of Comparative Neurology 308: 277–292.
Stuesse, S. L., W. L. R. Cruce, and R. G. Northcutt. 1991. Serotonergic and enkephalinergic cell groups in the brain stem of the bat ray and two skates. Brain, Behavior and Evolution 38: 39–52.
Stuesse, S. L., W. L. R. Cruce, and R. G. Northcutt. 1994. Localization of catecholamines in the brains of Chondrichthyes (cartilaginous fishes), PP. 21–47 IN: W. J. A. J. Smeets and A. J. Reiner, editors Phylogeny and Development of Catecholamine Systems in the CNS of Vertebrates. Cambridge, U.K.: Cambridge University Press.
Webb, J. F., and R. G. Northcutt. 1991. Ciliated epidermal cells in non-teleost actinopterygian fishes. Acta Zoologica 72: 107–111.
Webb, J. F., and R. G. Northcutt. 1997. Morphology and distribution of pit organs and canal neuromasts in non-teleost bony fishes. Brain, Behavior and Evolution 50: 139–151.
Weigle, C., and R. G. Northcutt. 1999. The chemoarchitecture of the forebrain of lampreys: evolutionary implications by comparisons with gnathostomes. European Journal of Morphology 37: 122–125.
Wicht, H., and R. G. Northcutt. 1990. Retinofugal and retinopetal projections in the Pacific hagfish, Eptatretus stouti (Myxinoidea). Brain, Behavior and Evolution 36: 315–328.
Wicht, H., and R. G. Northcutt. 1992. FMRFamide-like immunoreactivity in the brain of the Pacific hagfish, Eptatretus stouti (Myxinoidea). Cell and Tissue Research 270: 443–449.
Wicht, H., and R. G. Northcutt. 1992. The forebrain of the Pacific hagfish: a cladistic reconstruction of the ancestral craniate forebrain. Brain, Behavior and Evolution 40: 25–64.
Wicht, H., and R. G. Northcutt. 1993. Secondary olfactory projections and pallial topography in the Pacific hagfish, Eptatretus stouti. Journal of Comparative Neurology 337: 529–542.
Wicht, H., and R. G. Northcutt. 1994. An immunohistochemical study of the telencephalon and diencephalon in a myxinoid jawless fish, the Pacific hagfish, Eptatretus stouti. Brain, Behavior and Evolution 43: 140–161.
Wicht, H., and R. G. Northcutt. 1994. Observations on the development of the lateral line system in the Pacific hagfish (Eptatretus stouti, Myxinoidea). European Journal of Morphology 32: 257–261.
Wicht, H., and R. G. Northcutt. 1995. Ontogeny of the head of the Pacific hagfish (Eptatretus stouti, Myxinoidea): development of the lateral line system. Philosophical Transactions of the Royal Society of London B 349: 119–134.
Wicht, H., and R. G. Northcutt. 1998. Telencephalic connections in the Pacific hagfish (Eptatretus stouti), with special reference to the thalamopallial system. Journal of Comparative Neurology 395: 245–260.
Wilczynski, W., and R. G. Northcutt. 1977. Afferents to the optic tectum of the leopard frog: an HRP study. Journal of Comparative Neurology 173: 219–230.
Wilczynski, W., and R. G. Northcutt. 1983. Connections of the bullfrog striatum: afferent organization. Journal of Comparative Neurology 214: 321–332.
Wilczynski, W., and R. G. Northcutt. 1983. Connections of the bullfrog striatum: efferent projections. Journal of Comparative Neurology 214: 333–343.
Wullimann, M. F., D. L. Meyer, and R. G. Northcutt. 1991. The visually related posterior pretectal nucleus in the non-percomorph teleost Osteoglossum bicirrhosum projects to the hypothalamus: a DiI study. Journal of Comparative Neurology 312: 415–435.
Wullimann, M. F., and R. G. Northcutt. 1988. Connections of the corpus cerebelli in the green sunfish and in the common goldfish: a comparison of perciform and cypriniform teleosts. Brain, Behavior and Evolution 32: 293–316.
Wullimann, M. F., and R. G. Northcutt. 1989. Afferent connections of the valvula cerebelli in two teleosts, the common goldfish and the green sunfish. Journal of Comparative Neurology 289: 554–567.
Wullimann, M. F., and R. G. Northcutt. 1990. Visual and electrosensory circuits of the diencephalon in mormyrids: an evolutionary perspective. Journal of Comparative Neurology 297: 537–552.
