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York AR, Sherwood CC, Manger PR, Kaas JH, Mota B, Herculano-Houzel S. Folding of the cerebellar cortex is clade-specific in form but universal in degree. J Comp Neurol 2024; 532:e25616. [PMID: 38634526 DOI: 10.1002/cne.25616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 02/01/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024]
Abstract
Like the cerebralcortex, the surface of the cerebellum is repeatedly folded. Unlike the cerebralcortex, however, cerebellar folds are much thinner and more numerous; repeatthemselves largely along a single direction, forming accordion-like folds transverseto the mid-sagittal plane; and occur in all but the smallest cerebella. We haveshown previously that while the location of folds in mammalian cerebral cortex isclade-specific, the overall degree of folding strictly follows a universalpower law relating cortical thickness and the exposed and total surface areas predictedfrom the minimization of the effective free energy of an expanding, self-avoidingsurface of a certain thickness. Here we show that this scaling law extends tothe folding of the mid-sagittal sections of the cerebellum of 53 speciesbelonging to six mammalian clades. Simultaneously, we show that each clade hasa previously unsuspected distinctive spatial pattern of folding evident at themid-sagittal surface of the cerebellum. We note, however, that the mammaliancerebellum folds as a multi-fractal object, because of the difference betweenthe outside-in development of the cerebellar cortex around a preexisting coreof already connected white matter, compared to the inside-out development ofthe cerebral cortex with a white matter volume that develops as the cerebralcortex itself gains neurons. We conclude that repeated folding, one of the mostrecognizable features of biology, can arise simply from the interplay betweenthe universal applicability of the physics of self-organization and biological,phylogenetical clade-specific contingency, without the need for invokingselective pressures in evolution.
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Affiliation(s)
- Annaleigh R York
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
| | - Chet C Sherwood
- Department of Anthropology, The George Washington University, Washington, District of Columbia, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee, USA
| | - Bruno Mota
- Institute of Physics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee, USA
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Magielse N, Heuer K, Toro R, Schutter DJLG, Valk SL. A Comparative Perspective on the Cerebello-Cerebral System and Its Link to Cognition. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1293-1307. [PMID: 36417091 PMCID: PMC10657313 DOI: 10.1007/s12311-022-01495-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/11/2022] [Indexed: 11/24/2022]
Abstract
The longstanding idea that the cerebral cortex is the main neural correlate of human cognition can be elaborated by comparative analyses along the vertebrate phylogenetic tree that support the view that the cerebello-cerebral system is suited to support non-motor functions more generally. In humans, diverse accounts have illustrated cerebellar involvement in cognitive functions. Although the neocortex, and its transmodal association cortices such as the prefrontal cortex, have become disproportionately large over primate evolution specifically, human neocortical volume does not appear to be exceptional relative to the variability within primates. Rather, several lines of evidence indicate that the exceptional volumetric increase of the lateral cerebellum in conjunction with its connectivity with the cerebral cortical system may be linked to non-motor functions and mental operation in primates. This idea is supported by diverging cerebello-cerebral adaptations that potentially coevolve with cognitive abilities across other vertebrates such as dolphins, parrots, and elephants. Modular adaptations upon the vertebrate cerebello-cerebral system may thus help better understand the neuroevolutionary trajectory of the primate brain and its relation to cognition in humans. Lateral cerebellar lobules crura I-II and their reciprocal connections to the cerebral cortical association areas appear to have substantially expanded in great apes, and humans. This, along with the notable increase in the ventral portions of the dentate nucleus and a shift to increased relative prefrontal-cerebellar connectivity, suggests that modular cerebellar adaptations support cognitive functions in humans. In sum, we show how comparative neuroscience provides new avenues to broaden our understanding of cerebellar and cerebello-cerebral functions in the context of cognition.
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Affiliation(s)
- Neville Magielse
- Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Research Center Jülich, Jülich, Germany
- Otto Hahn Cognitive Neurogenetics Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Institute of Systems Neuroscience, Heinrich Heine University, Düsseldorf, Germany
| | - Katja Heuer
- Institute Pasteur, Unité de Neuroanatomie Appliquée et Théorique, Université Paris Cité, Paris, France
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Roberto Toro
- Institute Pasteur, Unité de Neuroanatomie Appliquée et Théorique, Université Paris Cité, Paris, France
| | - Dennis J L G Schutter
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | - Sofie L Valk
- Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Research Center Jülich, Jülich, Germany.
- Otto Hahn Cognitive Neurogenetics Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
- Institute of Systems Neuroscience, Heinrich Heine University, Düsseldorf, Germany.
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Magielse N, Toro R, Steigauf V, Abbaspour M, Eickhoff SB, Heuer K, Valk SL. Phylogenetic comparative analysis of the cerebello-cerebral system in 34 species highlights primate-general expansion of cerebellar crura I-II. Commun Biol 2023; 6:1188. [PMID: 37993596 PMCID: PMC10665558 DOI: 10.1038/s42003-023-05553-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 11/07/2023] [Indexed: 11/24/2023] Open
Abstract
The reciprocal connections between the cerebellum and the cerebrum have been suggested to simultaneously play a role in brain size increase and to support a broad array of brain functions in primates. The cerebello-cerebral system has undergone marked functionally relevant reorganization. In particular, the lateral cerebellar lobules crura I-II (the ansiform) have been suggested to be expanded in hominoids. Here, we manually segmented 63 cerebella (34 primate species; 9 infraorders) and 30 ansiforms (13 species; 8 infraorders) to understand how their volumes have evolved over the primate lineage. Together, our analyses support proportional cerebellar-cerebral scaling, whereas ansiforms have expanded faster than the cerebellum and cerebrum. We did not find different scaling between strepsirrhines and haplorhines, nor between apes and non-apes. In sum, our study shows primate-general structural reorganization of the ansiform, relative to the cerebello-cerebral system, which is relevant for specialized brain functions in an evolutionary context.
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Grants
- RT and KH are supported by the French Agence Nationale de la Recherche, projects NeuroWebLab (ANR-19-DATA-0025) and DMOBE (ANR-21-CE45-0016). KH received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No101033485 (Individual Fellowship). Last, this work was funded in part by Helmholtz Association’s Initiative and Networking Fund under the Helmholtz International Lab grant agreement InterLabs-0015, and the Canada First Research Excellence Fund (CFREF Competition 2, 2015–2016), awarded to the Healthy Brains, Healthy Lives initiative at McGill University, through the Helmholtz International BigBrain Analytics and Learning Laboratory (HIBALL), including NM, SBE, and SLV.
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Affiliation(s)
- Neville Magielse
- Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Research Center Jülich, Wilhelm-Johnen-Straße, 52428, Jülich, Germany.
- Otto Hahn Cognitive Neurogenetics Group, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103, Leipzig, Germany.
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
| | - Roberto Toro
- Institut Pasteur, Unité de Neuroanatomie Appliquée et Théorique, Université Paris Cité, 25 rue du Dr. Roux, 75724, Paris, France
| | - Vanessa Steigauf
- Department of Biology, Northern Michigan University, 1401 Presque Isle Ave, MI, 49855, Marquette, USA
| | - Mahta Abbaspour
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Haus 1, 10117, Berlin, Germany
- Department of Neurology, Charité - Universitätsmedizin Berlin, Bonhoefferweg 3, 10117, Berlin, Germany
| | - Simon B Eickhoff
- Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Research Center Jülich, Wilhelm-Johnen-Straße, 52428, Jülich, Germany
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany
| | - Katja Heuer
- Institut Pasteur, Unité de Neuroanatomie Appliquée et Théorique, Université Paris Cité, 25 rue du Dr. Roux, 75724, Paris, France
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103, Leipzig, Germany
| | - Sofie L Valk
- Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Research Center Jülich, Wilhelm-Johnen-Straße, 52428, Jülich, Germany.
- Otto Hahn Cognitive Neurogenetics Group, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103, Leipzig, Germany.
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
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Longren LL, Eigen L, Shubitidze A, Lieschnegg O, Baum D, Nyakatura JA, Hildebrandt T, Brecht M. Dense reconstruction of elephant trunk musculature. Curr Biol 2023; 33:4713-4720.e3. [PMID: 37757829 DOI: 10.1016/j.cub.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 08/15/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023]
Abstract
The elephant trunk operates as a muscular hydrostat1,2 and is actuated by the most complex musculature known in animals.3,4 Because the number of trunk muscles is unclear,5 we performed dense reconstructions of trunk muscle fascicles, elementary muscle units, from microCT scans of an Asian baby elephant trunk. Muscle architecture changes markedly across the trunk. Trunk tip and finger consist of about 8,000 extraordinarily filigree fascicles. The dexterous finger consists exclusively of microscopic radial fascicles pointing to a role of muscle miniaturization in elephant dexterity. Radial fascicles also predominate (at 82% volume) the remainder of the trunk tip, and we wonder if radial muscle fascicles are of particular significance for fine motor control of the dexterous trunk tip. By volume, trunk-shaft muscles6 comprise one-third of the numerous, small radial muscle fascicles; two-thirds of the three subtypes of large longitudinal fascicles (dorsal longitudinals, ventral outer obliques, and ventral inner obliques);7,8,9 and a small fraction of transversal fascicles. Shaft musculature is laterally, but not radially, symmetric. A predominance of dorsal over ventral radial muscles and of ventral over dorsal longitudinal muscles may result in a larger ability of the shaft to extend dorsally than ventrally10 and to bend inward rather than outward. There are around 90,000 trunk muscle fascicles. While primate hand control is based on fine control of contraction by the convergence of many motor neurons on a small set of relatively large muscles, evolution of elephant grasping has led to thousands of microscopic fascicles, which probably outnumber facial motor neurons.
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Affiliation(s)
- Luke L Longren
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany; Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Lennart Eigen
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
| | - Ani Shubitidze
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
| | - Oliver Lieschnegg
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
| | - Daniel Baum
- Zuse-Institut Berlin, Takustraße 7, 14195 Berlin, Germany
| | - John A Nyakatura
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Thomas Hildebrandt
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany; NeuroCure Cluster of Excellence, Humboldt-Universität zu Berlin, 10115 Berlin, Germany.
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5
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Heuer K, Traut N, de Sousa AA, Valk SL, Clavel J, Toro R. Diversity and evolution of cerebellar folding in mammals. eLife 2023; 12:e85907. [PMID: 37737580 PMCID: PMC10617990 DOI: 10.7554/elife.85907] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 09/22/2023] [Indexed: 09/23/2023] Open
Abstract
The process of brain folding is thought to play an important role in the development and organisation of the cerebrum and the cerebellum. The study of cerebellar folding is challenging due to the small size and abundance of its folia. In consequence, little is known about its anatomical diversity and evolution. We constituted an open collection of histological data from 56 mammalian species and manually segmented the cerebrum and the cerebellum. We developed methods to measure the geometry of cerebellar folia and to estimate the thickness of the molecular layer. We used phylogenetic comparative methods to study the diversity and evolution of cerebellar folding and its relationship with the anatomy of the cerebrum. Our results show that the evolution of cerebellar and cerebral anatomy follows a stabilising selection process. We observed two groups of phenotypes changing concertedly through evolution: a group of 'diverse' phenotypes - varying over several orders of magnitude together with body size, and a group of 'stable' phenotypes varying over less than 1 order of magnitude across species. Our analyses confirmed the strong correlation between cerebral and cerebellar volumes across species, and showed in addition that large cerebella are disproportionately more folded than smaller ones. Compared with the extreme variations in cerebellar surface area, folial anatomy and molecular layer thickness varied only slightly, showing a much smaller increase in the larger cerebella. We discuss how these findings could provide new insights into the diversity and evolution of cerebellar folding, the mechanisms of cerebellar and cerebral folding, and their potential influence on the organisation of the brain across species.
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Affiliation(s)
- Katja Heuer
- Institut Pasteur, Université Paris Cité, Unité de Neuroanatomie Appliquée et ThéoriqueParisFrance
| | - Nicolas Traut
- Institut Pasteur, Université Paris Cité, Unité de Neuroanatomie Appliquée et ThéoriqueParisFrance
| | | | - Sofie Louise Valk
- Otto Hahn Group Cognitive Neurogenetics, Max Planck Institute for Human Cognitive and Brain SciencesLeipzigGermany
- Institute of Neuroscience and Medicine, Brain & Behaviour (INM-7), Research Centre Jülich, FZ JülichJülichGermany
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Julien Clavel
- Université Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNAVilleurbanneFrance
| | - Roberto Toro
- Institut Pasteur, Université Paris Cité, Unité de Neuroanatomie Appliquée et ThéoriqueParisFrance
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6
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Kaufmann LV, Schneeweiß U, Maier E, Hildebrandt T, Brecht M. Elephant facial motor control. SCIENCE ADVANCES 2022; 8:eabq2789. [PMID: 36288305 PMCID: PMC9604532 DOI: 10.1126/sciadv.abq2789] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/06/2022] [Indexed: 06/10/2023]
Abstract
We studied facial motor control in elephants, animals with muscular dexterous trunks. Facial nucleus neurons (~54,000 in Asian elephants, ~63,000 in African elephants) outnumbered those of other land-living mammals. The large-eared African elephants had more medial facial subnucleus neurons than Asian elephants, reflecting a numerically more extensive ear-motor control. Elephant dorsal and lateral facial subnuclei were unusual in elongation, neuron numerosity, and a proximal-to-distal neuron size increase. We suggest that this subnucleus organization is related to trunk representation, with the huge distal neurons innervating the trunk tip with long axons. African elephants pinch objects with two trunk tip fingers, whereas Asian elephants grasp/wrap objects with larger parts of their trunk. Finger "motor foveae" and a positional bias of neurons toward the trunk tip representation in African elephant facial nuclei reflect their motor strategy. Thus, elephant brains reveal neural adaptations to facial morphology, body size, and dexterity.
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Affiliation(s)
- Lena V. Kaufmann
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Undine Schneeweiß
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
| | - Eduard Maier
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
| | - Thomas Hildebrandt
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, D-10315 Berlin, Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115 Berlin, Germany
- NeuroCure Cluster of Excellence, Humboldt-Universität zu Berlin, Berlin, Germany
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7
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Chusyd DE, Ackermans NL, Austad SN, Hof PR, Mielke MM, Sherwood CC, Allison DB. Aging: What We Can Learn From Elephants. FRONTIERS IN AGING 2021; 2:726714. [PMID: 35822016 PMCID: PMC9261397 DOI: 10.3389/fragi.2021.726714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/03/2021] [Indexed: 11/13/2022]
Abstract
Elephants are large-brained, social mammals with a long lifespan. Studies of elephants can provide insight into the aging process, which may be relevant to understanding diseases that affect elderly humans because of their shared characteristics that have arisen through independent evolution. Elephants become sexually mature at 12 to 14 years of age and are known to live into, and past, their 7th decade of life. Because of their relatively long lifespans, elephants may have evolved mechanisms to counter age-associated morbidities, such as cancer and cognitive decline. Elephants rely heavily on their memory, and engage in multiple levels of competitive and collaborative relationships because they live in a fission-fusion system. Female matrilineal relatives and dependent offspring form tight family units led by an older-aged matriarch, who serves as the primary repository for social and ecological knowledge in the herd. Similar to humans, elephants demonstrate a dependence on social bonds, memory, and cognition to navigate their environment, behaviors that might be associated with specializations of brain anatomy. Compared with other mammals, the elephant hippocampus is proportionally smaller, whereas the temporal lobe is disproportionately large and expands laterally. The elephant cerebellum is also relatively enlarged, and the cerebral cortex is highly convoluted with numerous gyral folds, more than in humans. Last, an interesting characteristic unique to elephants is the presence of at least 20 copies of the TP53 tumor suppressor gene. Humans have only a single copy. TP53 encodes for the p53 protein, which is known to orchestrate cellular response to DNA damage. The effects of these multiple copies of TP53 are still being investigated, but it may be to protect elephants against multiple age-related diseases. For these reasons, among others, studies of elephants would be highly informative for aging research. Elephants present an underappreciated opportunity to explore further common principles of aging in a large-brained mammal with extended longevity. Such research can contribute to contextualizing our knowledge of age-associated morbidities in humans.
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Affiliation(s)
- Daniella E. Chusyd
- Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN, United States
- *Correspondence: Daniella E. Chusyd,
| | - Nicole L. Ackermans
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Steven N. Austad
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, United States
- Nathan Shock Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Patrick R. Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Michelle M. Mielke
- Division of Epidemiology, Department of Quantitative Health Sciences and Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC, United States
| | - David B. Allison
- Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN, United States
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8
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Al-Hussain SM, Yousuf MS, Hani AB, Zaqout S, Djouhri L, Mustafa AG. A Golgi study of neurons in the camel cerebellum (Camelus dromedarius). Anat Rec (Hoboken) 2021; 305:1264-1276. [PMID: 34390196 DOI: 10.1002/ar.24742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/14/2021] [Accepted: 07/05/2021] [Indexed: 11/08/2022]
Abstract
Neurons in the cerebellar cortex of camels were studied using modified Golgi impregnation methods. Neurons were classified according to their position, morphology of their soma, density and distribution of dendrites, and the course of their axons. Accordingly, eight types of neurons were identified. Three types were found in the molecular layer: upper and lower stellate cells and basket cells, and four types were found in the granular layer: granule cells, Golgi Type II cells, Lugaro cells, and unipolar brush cells. Only the somata of Purkinje cells were found in the Purkinje cell layer. The molecular layer is characterized by the presence of more dendrites, dendritic spines, and transverse fibers. Golgi cells also show extensive dendritic branching and spines. The results illustrate the neuronal features of the camel cerebellum as a large mammal living in harsh environmental conditions. These findings should contribute to advancing our understanding of species-comparative anatomy in achieving better coordination of motor activity.
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Affiliation(s)
- Saleh M Al-Hussain
- Department of Anatomy, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan
| | - Mustafa S Yousuf
- Department of Basic Medical Sciences, Faculty of Medicine, Hashemite University, Zarqa, Jordan
| | - Ayat Bani Hani
- Department of Rehabilitation Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Sami Zaqout
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.,Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Laiche Djouhri
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.,Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Ayman G Mustafa
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.,Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
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9
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Herculano-Houzel S, da Cunha FB, Reed JL, Kaswera-Kyamakya C, Gillissen E, Manger PR. Microchiropterans have a diminutive cerebral cortex, not an enlarged cerebellum, compared to megachiropterans and other mammals. J Comp Neurol 2020; 528:2978-2993. [PMID: 32656795 DOI: 10.1002/cne.24985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 11/11/2022]
Abstract
Small echolocating bats are set apart from most other mammals by their relatively large cerebellum, a feature that has been associated to echolocation, as it is presumed to indicate a relatively enlarged number of neurons in the cerebellum in comparison to other brain structures. Here we quantify the neuronal composition of the cerebral cortex, cerebellum and remaining brain structures of seven species of large Pteropodid bats (formerly classified as megachiropterans), one of which echolocates, and six species of small bats (formerly classified as microchiropterans), all of which echolocate. This chiropteran data is compared to 60 mammalian species in our dataset to determine whether the relatively large cerebellum of the small echolocating bats, and possibly that of the echolocating Pteropodid, contains a relatively enlarged number of neurons. We find no evidence that the distribution of neurons differs between microchiropterans and megachiropterans, but our data indicate that microchiropterans, like the smallest shrew in our dataset, have diminutive cerebral cortices, which makes the cerebellum appear relatively large. We propose that, in agreement with the diminutive brain size of the earliest fossil mammals, this is a plesiomorphic, not a derived, feature of microchiropteran brains. The results of this study also reveal important neural characteristics related to the phylogenetic affinities and relationships of the chiropterans.
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Affiliation(s)
- Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA.,Department Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee, USA
| | - Felipe Barros da Cunha
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,University of Lethbridge, Lethbridge, Canada
| | - Jamie L Reed
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Emmanuel Gillissen
- Department of African Zoology, Royal Museum for Central Africa, Tervuren, Belgium.,Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, Belgium.,Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, USA
| | - Paul R Manger
- School of Anatomical Sciences, University of the Witwatersrand, South Africa
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10
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Chengetanai S, Tenley JD, Bertelsen MF, Hård T, Bhagwandin A, Haagensen M, Tang CY, Wang VX, Wicinski B, Hof PR, Manger PR, Spocter MA. Brain of the African wild dog. I. Anatomy, architecture, and volumetrics. J Comp Neurol 2020; 528:3245-3261. [PMID: 32720707 DOI: 10.1002/cne.24999] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 02/05/2023]
Abstract
The African wild dog is endemic to sub-Saharan Africa and belongs to the family Canidae which includes domestic dogs and their closest relatives (i.e., wolves, coyotes, jackals, dingoes, and foxes). The African wild dog is known for its highly social behavior, co-ordinated pack predation, and striking vocal repertoire, but little is known about its brain and whether it differs in any significant way from that of other canids. We employed gross anatomical observation, magnetic resonance imaging, and classical neuroanatomical staining to provide a broad overview of the structure of the African wild dog brain. Our results reveal a mean brain mass of 154.08 g, with an encephalization quotient of 1.73, indicating that the African wild dog has a relatively large brain size. Analysis of the various structures that comprise their brains and their topological inter-relationships, as well as the areas and volumes of the corpus callosum, ventricular system, hippocampus, amygdala, cerebellum and the gyrification index, all reveal that the African wild dog brain is, in general, similar to that of other mammals, and very similar to that of other carnivorans. While at this level of analysis we do not find any striking specializations within the brain of the African wild dog, apart from a relatively large brain size, the observations made indicate that more detailed analyses of specific neural systems, particularly those involved in sensorimotor processing, sociality or cognition, may reveal features that are either unique to this species or shared among the Canidae to the exclusion of other Carnivora.
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Affiliation(s)
- Samson Chengetanai
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Mads F Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Fredericksberg, Denmark
| | | | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mark Haagensen
- Department of Radiology, University of Witwatersrand-Donald Gordon Medical Centre, Johannesburg, South Africa
| | - Cheuk Y Tang
- Department of Psychiatry, and BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Victoria X Wang
- Department of Psychiatry, and BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Bridget Wicinski
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Patrick R Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, USA.,College of Veterinary Medicine, Department of Biomedical Sciences, Iowa State University, Ames, Iowa, USA
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11
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Malungo IB, Gravett N, Bhagwandin A, Davimes JG, Manger PR. A Preliminary Description of the Sleep-Related Neural Systems in the Brain of the Blue Wildebeest, Connochaetes taurinus. Anat Rec (Hoboken) 2019; 303:1977-1997. [PMID: 31513360 DOI: 10.1002/ar.24265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/12/2019] [Accepted: 07/16/2019] [Indexed: 12/18/2022]
Abstract
The current study provides a detailed qualitative description of the organization of the cholinergic, catecholaminergic, serotonergic, orexinergic, and GABAergic sleep-related systems in the brain of the blue wildebeest (Connocheates taurinus), along with a quantitative analysis of the pontine cholinergic and noradrenergic neurons, and the hypothalamic orexinergic neurons. The aim of this study was to compare the nuclear organization of these systems to other mammalian species and specifically that reported for other Cetartiodactyla. In the brain of the blue wildebeest, from the basal forebrain to the pons, the nuclear organization of the cholinergic, catecholaminergic, serotonergic, and orexinergic systems, for the most part, showed a corresponding nuclear organization to that reported in other mammals and more specifically the Cetartiodactyla. Furthermore, the description and distribution of the GABAergic system, which was examined through immunostaining for the calcium binding proteins calbindin, calretinin, and parvalbumin, was also similar to that seen in other mammals. These findings indicate that sleep in the blue wildebeest is likely to show typically mammalian features in terms of the global brain activity of the generally recognized sleep states of mammals, but Cetartiodactyl-specific features of the orexinergic system may act to lower overall daily total sleep time in relation to similar sized non-Cetartiodactyl mammals. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1977-1997, 2020. © 2019 American Association for Anatomy.
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Affiliation(s)
- Illke B Malungo
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nadine Gravett
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Joshua G Davimes
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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12
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Powell LE, Barton RA, Street SE. Maternal investment, life histories and the evolution of brain structure in primates. Proc Biol Sci 2019; 286:20191608. [PMID: 31530145 PMCID: PMC6784728 DOI: 10.1098/rspb.2019.1608] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 08/15/2019] [Indexed: 12/16/2022] Open
Abstract
Life history is a robust correlate of relative brain size: larger-brained mammals and birds have slower life histories and longer lifespans than smaller-brained species. The cognitive buffer hypothesis (CBH) proposes an adaptive explanation for this relationship: large brains may permit greater behavioural flexibility and thereby buffer the animal from unpredictable environmental challenges, allowing for reduced mortality and increased lifespan. By contrast, the developmental costs hypothesis (DCH) suggests that life-history correlates of brain size reflect the extension of maturational processes needed to accommodate the evolution of large brains, predicting correlations with pre-adult life-history phases. Here, we test novel predictions of the hypotheses in primates applied to the neocortex and cerebellum, two major brain structures with distinct developmental trajectories. While neocortical growth is allocated primarily to pre-natal development, the cerebellum exhibits relatively substantial post-natal growth. Consistent with the DCH, neocortical expansion is related primarily to extended gestation while cerebellar expansion to extended post-natal development, particularly the juvenile period. Contrary to the CBH, adult lifespan explains relatively little variance in the whole brain or neocortex volume once pre-adult life-history phases are accounted for. Only the cerebellum shows a relationship with lifespan after accounting for developmental periods. Our results substantiate and elaborate on the role of maternal investment and offspring development in brain evolution, suggest that brain components can evolve partly independently through modifications of distinct developmental phases, and imply that environmental input during post-natal maturation may be particularly crucial for the development of cerebellar function. They also suggest that relatively extended post-natal maturation times provide a developmental mechanism for the marked expansion of the cerebellum in the apes.
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Affiliation(s)
- Lauren E. Powell
- Evolutionary Anthropology Research Group, Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK
| | | | - Sally E. Street
- Evolutionary Anthropology Research Group, Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK
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13
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Muller AS, Montgomery SH. Co-evolution of cerebral and cerebellar expansion in cetaceans. J Evol Biol 2019; 32:1418-1431. [PMID: 31507000 PMCID: PMC6916408 DOI: 10.1111/jeb.13539] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/27/2019] [Indexed: 12/23/2022]
Abstract
Cetaceans possess brains that rank among the largest to have ever evolved, either in terms of absolute mass or relative to body size. Cetaceans have evolved these huge brains under relatively unique environmental conditions, making them a fascinating case study to investigate the constraints and selection pressures that shape how brains evolve. Indeed, cetaceans have some unusual neuroanatomical features, including a thin but highly folded cerebrum with low cortical neuron density, as well as many structural adaptations associated with acoustic communication. Previous reports also suggest that at least some cetaceans have an expanded cerebellum, a brain structure with wide‐ranging functions in adaptive filtering of sensory information, the control of motor actions, and cognition. Here, we report that, relative to the size of the rest of the brain, both the cerebrum and cerebellum are dramatically enlarged in cetaceans and show evidence of co‐evolution, a pattern of brain evolution that is convergent with primates. However, we also highlight several branches where cortico‐cerebellar co‐evolution may be partially decoupled, suggesting these structures can respond to independent selection pressures. Across cetaceans, we find no evidence of a simple linear relationship between either cerebrum and cerebellum size and the complexity of social ecology or acoustic communication, but do find evidence that their expansion may be associated with dietary breadth. In addition, our results suggest that major increases in both cerebrum and cerebellum size occurred early in cetacean evolution, prior to the origin of the major extant clades, and predate the evolution of echolocation.
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Affiliation(s)
| | - Stephen Hugh Montgomery
- Department of Zoology, University of Cambridge, Cambridge, UK.,School of Biological Sciences, University of Bristol, Bristol, UK
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14
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Smaers JB, Turner AH, Gómez-Robles A, Sherwood CC. A cerebellar substrate for cognition evolved multiple times independently in mammals. eLife 2018; 7:e35696. [PMID: 29809137 PMCID: PMC6003771 DOI: 10.7554/elife.35696] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/21/2018] [Indexed: 12/21/2022] Open
Abstract
Given that complex behavior evolved multiple times independently in different lineages, a crucial question is whether these independent evolutionary events coincided with modifications to common neural systems. To test this question in mammals, we investigate the lateral cerebellum, a neurobiological system that is novel to mammals, and is associated with higher cognitive functions. We map the evolutionary diversification of the mammalian cerebellum and find that relative volumetric changes of the lateral cerebellar hemispheres (independent of cerebellar size) are correlated with measures of domain-general cognition in primates, and are characterized by a combination of parallel and convergent shifts towards similar levels of expansion in distantly related mammalian lineages. Results suggest that multiple independent evolutionary occurrences of increased behavioral complexity in mammals may at least partly be explained by selection on a common neural system, the cerebellum, which may have been subject to multiple independent neurodevelopmental remodeling events during mammalian evolution.
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Affiliation(s)
- Jeroen B Smaers
- Department of AnthropologyStony Brook UniversityNew YorkUnited States
- Center for the Advanced Study of Human PaleobiologyStony Brook UniversityNew YorkUnited States
| | - Alan H Turner
- Department of Anatomical SciencesStony Brook UniversityNew YorkUnited States
| | - Aida Gómez-Robles
- Department of Genetics, Evolution and EnvironmentUniversity College LondonLondonUnited Kingdom
- Department of AnthropologyThe George Washington UniversityWashingtonUnited States
| | - Chet C Sherwood
- Department of AnthropologyThe George Washington UniversityWashingtonUnited States
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15
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Bielert C, Costo N, Gallup A. Tuskedness in African elephants – an anatomical investigation of laterality. J Zool (1987) 2017. [DOI: 10.1111/jzo.12511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- C. Bielert
- Department of Psychology State University of New York at Oneonta Oneonta NY USA
| | - N. Costo
- Department of Psychology State University of New York at Oneonta Oneonta NY USA
| | - A. Gallup
- Department of Social and Behavioral Sciences SUNY Polytechnic Institute Utica NY USA
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16
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Bhagwandin A, Haagensen M, Manger PR. The Brain of the Black ( Diceros bicornis) and White ( Ceratotherium simum) African Rhinoceroses: Morphology and Volumetrics from Magnetic Resonance Imaging. Front Neuroanat 2017; 11:74. [PMID: 28912691 PMCID: PMC5583206 DOI: 10.3389/fnana.2017.00074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/15/2017] [Indexed: 12/22/2022] Open
Abstract
The morphology and volumetrics of the understudied brains of two iconic large terrestrial African mammals: the black (Diceros bicornis) and white (Ceratotherium simum) rhinoceroses are described. The black rhinoceros is typically solitary whereas the white rhinoceros is social, and both are members of the Perissodactyl order. Here, we provide descriptions of the surface of the brain of each rhinoceros. For both species, we use magnetic resonance images (MRI) to develop a description of the internal anatomy of the rhinoceros brain and to calculate the volume of the amygdala, cerebellum, corpus callosum, hippocampus, and ventricular system as well as to determine the gyrencephalic index. The morphology of both black and white rhinoceros brains is very similar to each other, although certain minor differences, seemingly related to diet, were noted, and both brains evince the general anatomy of the mammalian brain. The rhinoceros brains display no obvious neuroanatomical specializations in comparison to other mammals previously studied. In addition, the volumetric analyses indicate that the size of the various regions of the rhinoceros brain measured, as well as the extent of gyrification, are what would be predicted for a mammal with their brain mass when compared allometrically to previously published data. We conclude that the brains of the black and white rhinoceros exhibit a typically mammalian organization at a superficial level, but histological studies may reveal specializations of interest in relation to rhinoceros behavior.
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Affiliation(s)
- Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburg, South Africa
| | - Mark Haagensen
- Department of Radiology, Wits Donald Gordon Medical Centre, University of the WitwatersrandJohannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburg, South Africa
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17
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Imam A, Ajao MS, Bhagwandin A, Ihunwo AO, Manger PR. The brain of the tree pangolin (Manis tricuspis
). I. General appearance of the central nervous system. J Comp Neurol 2017; 525:2571-2582. [DOI: 10.1002/cne.24222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Aminu Imam
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
- Department of Anatomy; Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Moyosore S. Ajao
- Department of Anatomy; Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Adhil Bhagwandin
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
| | - Amadi O. Ihunwo
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
| | - Paul R. Manger
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
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18
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Kuhrt H, Bringmann A, Härtig W, Wibbelt G, Peichl L, Reichenbach A. The Retina of Asian and African Elephants: Comparison of Newborn and Adult. BRAIN, BEHAVIOR AND EVOLUTION 2017; 89:84-103. [PMID: 28437785 DOI: 10.1159/000464097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 02/14/2017] [Indexed: 11/19/2022]
Abstract
Elephants are precocial mammals that are relatively mature as newborns and mobile shortly after birth. To determine whether the retina of newborn elephants is capable of supporting the mobility of elephant calves, we compared the retinal structures of 2 newborn elephants (1 African and 1 Asian) and 2 adult animals of both species by immunohistochemical and morphometric methods. For the first time, we present here a comprehensive qualitative and quantitative characterization of the cellular composition of the newborn and the adult retinas of 2 elephant species. We found that the retina of elephants is relatively mature at birth. All retinal layers were well discernible, and various retinal cell types were detected in the newborns, including Müller glial cells (expressing glutamine synthetase and cellular retinal binding protein; CRALBP), cone photoreceptors (expressing S-opsin or M/L-opsin), protein kinase Cα-expressing bipolar cells, tyrosine hydroxylase-, choline acetyltransferase (ChAT)-, calbindin-, and calretinin-expressing amacrine cells, and calbindin-expressing horizontal cells. The retina of newborn elephants contains discrete horizontal cells which coexpress ChAT, calbindin, and calretinin. While the overall structure of the retina is very similar between newborn and adult elephants, various parameters change after birth. The postnatal thickening of the retinal ganglion cell axons and the increase in ganglion cell soma size are explained by the increase in body size after birth, and the decreases in the densities of neuronal and glial cells are explained by the postnatal expansion of the retinal surface area. The expression of glutamine synthetase and CRALBP in the Müller cells of newborn elephants suggests that the cells are already capable of supporting the activities of photoreceptors and neurons. As a peculiarity, the elephant retina contains both normally located and displaced giant ganglion cells, with single cells reaching a diameter of more than 50 µm in adults and therefore being almost in the range of giant retinal ganglion cells found in aquatic mammals. Some of these ganglion cells are displaced into the inner nuclear layer, a unique feature of terrestrial mammals. For the first time, we describe here the occurrence of many bistratified rod bipolar cells in the elephant retina. These bistratified bipolar cells may improve nocturnal contrast perception in elephants given their arrhythmic lifestyle.
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Affiliation(s)
- Heidrun Kuhrt
- Paul Flechsig Institute of Brain Research, University of Leipzig Medical Faculty, Leipzig, Germany
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19
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Ridgway SH, Carlin KP, Van Alstyne KR, Hanson AC, Tarpley RJ. Comparison of Dolphins' Body and Brain Measurements with Four Other Groups of Cetaceans Reveals Great Diversity. BRAIN, BEHAVIOR AND EVOLUTION 2017; 88:235-257. [PMID: 28122370 DOI: 10.1159/000454797] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 11/28/2016] [Indexed: 01/06/2023]
Abstract
We compared mature dolphins with 4 other groupings of mature cetaceans. With a large data set, we found great brain diversity among 5 different taxonomic groupings. The dolphins in our data set ranged in body mass from about 40 to 6,750 kg and in brain mass from 0.4 to 9.3 kg. Dolphin body length ranged from 1.3 to 7.6 m. In our combined data set from the 4 other groups of cetaceans, body mass ranged from about 20 to 120,000 kg and brain mass from about 0.2 to 9.2 kg, while body length varied from 1.21 to 26.8 m. Not all cetaceans have large brains relative to their body size. A few dolphins near human body size have human-sized brains. On the other hand, the absolute brain mass of some other cetaceans is only one-sixth as large. We found that brain volume relative to body mass decreases from Delphinidae to a group of Phocoenidae and Monodontidae, to a group of other odontocetes, to Balaenopteroidea, and finally to Balaenidae. We also found the same general trend when we compared brain volume relative to body length, except that the Delphinidae and Phocoenidae-Monodontidae groups do not differ significantly. The Balaenidae have the smallest relative brain mass and the lowest cerebral cortex surface area. Brain parts also vary. Relative to body mass and to body length, dolphins also have the largest cerebellums. Cortex surface area is isometric with brain size when we exclude the Balaenidae. Our data show that the brains of Balaenidae are less convoluted than those of the other cetaceans measured. Large vascular networks inside the cranial vault may help to maintain brain temperature, and these nonbrain tissues increase in volume with body mass and with body length ranging from 8 to 65% of the endocranial volume. Because endocranial vascular networks and other adnexa, such as the tentorium cerebelli, vary so much in different species, brain size measures from endocasts of some extinct cetaceans may be overestimates. Our regression of body length on endocranial adnexa might be used for better estimates of brain volume from endocasts or from endocranial volume of living species or extinct cetaceans.
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Affiliation(s)
- Sam H Ridgway
- National Marine Mammal Foundation, San Diego, CA, USA
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20
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Minervini S, Accogli G, Pirone A, Graïc JM, Cozzi B, Desantis S. Brain Mass and Encephalization Quotients in the Domestic Industrial Pig (Sus scrofa). PLoS One 2016; 11:e0157378. [PMID: 27351807 PMCID: PMC4924858 DOI: 10.1371/journal.pone.0157378] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 05/28/2016] [Indexed: 12/31/2022] Open
Abstract
In the present study we examined the brain of fetal, newborn, and adult pigs raised for meat production. The fresh and formalin-fixed weights of the brain have been recorded and used, together with body weight, to calculate the Encephalization Quotient (EQ). The weight of the cerebellum has been used to calculate the Cerebellar Quotient (CQ). The results have been discussed together with analogue data obtained in other terrestrial Cetartiodactyla (including the domestic bovine, sheep, goat, and camel), domesticated Carnivora, Proboscidata, and Primates. Our study, based on a relatively large experimental series, corrects former observations present in the literature based on smaller samples, and emphasizes that the domestic pig has a small brain relative to its body size (EQ = 0.38 for adults), possibly due to factors linked to the necessity of meat production and improved body weight. Comparison with other terrestrial Cetartiodactyla indicates a similar trend for all domesticated species.
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Affiliation(s)
- Serena Minervini
- Section of Veterinary Clinics and Animal Productions, Department of Emergency and Organ Transplantation (DETO), University of Bari Aldo Moro, Valenzano (Ba), Italy
| | - Gianluca Accogli
- Section of Veterinary Clinics and Animal Productions, Department of Emergency and Organ Transplantation (DETO), University of Bari Aldo Moro, Valenzano (Ba), Italy
| | - Andrea Pirone
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy
| | - Salvatore Desantis
- Section of Veterinary Clinics and Animal Productions, Department of Emergency and Organ Transplantation (DETO), University of Bari Aldo Moro, Valenzano (Ba), Italy
- * E-mail:
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21
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Ballarin C, Povinelli M, Granato A, Panin M, Corain L, Peruffo A, Cozzi B. The Brain of the Domestic Bos taurus: Weight, Encephalization and Cerebellar Quotients, and Comparison with Other Domestic and Wild Cetartiodactyla. PLoS One 2016; 11:e0154580. [PMID: 27128674 PMCID: PMC4851379 DOI: 10.1371/journal.pone.0154580] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/17/2016] [Indexed: 11/18/2022] Open
Abstract
The domestic bovine Bos taurus is raised worldwide for meat and milk production, or even for field work. However the functional anatomy of its central nervous system has received limited attention and most of the reported data in textbooks and reviews are derived from single specimens or relatively old literature. Here we report information on the brain of Bos taurus obtained by sampling 158 individuals, 150 of which at local abattoirs and 8 in the dissecting room, these latter subsequently formalin-fixed. Using body weight and fresh brain weight we calculated the Encephalization Quotient (EQ), and Cerebellar Quotient (CQ). Formalin-fixed brains sampled in the necropsy room were used to calculate the absolute and relative weight of the major components of the brain. The data that we obtained indicate that the domestic bovine Bos taurus possesses a large, convoluted brain, with a slightly lower weight than expected for an animal of its mass. Comparisons with other terrestrial and marine members of the order Cetartiodactyla suggested close similarity with other species with the same feeding adaptations, and with representative baleen whales. On the other hand differences with fish-hunting toothed whales suggest separate evolutionary pathways in brain evolution. Comparison with the other large domestic herbivore Equus caballus (belonging to the order Perissodactyla) indicates that Bos taurus underwent heavier selection of bodily traits, which is also possibly reflected in a comparatively lower EQ than in the horse. The data analyzed suggest that the brain of domestic bovine is potentially interesting for comparative neuroscience studies and may represents an alternative model to investigate neurodegeneration processes.
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Affiliation(s)
- Cristina Ballarin
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro (PD), Italy
| | - Michele Povinelli
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro (PD), Italy
| | - Alberto Granato
- Department of Psychology, Catholic University of Rome, Largo Gemelli 1, 20100 Milan (MI), Italy
| | - Mattia Panin
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro (PD), Italy
| | - Livio Corain
- Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, 36100 Vicenza (VI), Italy
| | - Antonella Peruffo
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro (PD), Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro (PD), Italy
- * E-mail:
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22
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Dell LA, Patzke N, Spocter MA, Bertelsen MF, Siegel JM, Manger PR. Organization of the sleep-related neural systems in the brain of the river hippopotamus (Hippopotamus amphibius): A most unusual cetartiodactyl species. J Comp Neurol 2016; 524:2036-58. [PMID: 26588600 DOI: 10.1002/cne.23930] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 11/09/2022]
Abstract
This study provides the first systematic analysis of the nuclear organization of the neural systems related to sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the river hippopotamus, one of the closest extant terrestrial relatives of the cetaceans. All nuclei involved in sleep regulation and control found in other mammals, including cetaceans, were present in the river hippopotamus, with no specific nuclei being absent, but novel features of the cholinergic system, including novel nuclei, were present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic, and orexinergic systems and is extended to the γ-aminobutyric acid (GABA)ergic elements of these nuclei. Quantitative analysis reveals that the numbers of pontine cholinergic (259,578) and noradrenergic (127,752) neurons, and hypothalamic orexinergic neurons (68,398) are markedly higher than in other large-brained mammals. These features, along with novel cholinergic nuclei in the intralaminar nuclei of the dorsal thalamus and the ventral tegmental area of the midbrain, as well as a major expansion of the hypothalamic cholinergic nuclei and a large laterodorsal tegmental nucleus of the pons that has both parvocellular and magnocellular cholinergic neurons, indicates an unusual sleep phenomenology for the hippopotamus. Our observations indicate that the hippopotamus is likely to be a bihemispheric sleeper that expresses REM sleep. The novel features of the cholinergic system suggest the presence of an undescribed sleep state in the hippopotamus, as well as the possibility that this animal could, more rapidly than other mammals, switch cortical electroencephalographic activity from one state to another. J. Comp. Neurol. 524:2036-2058, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Leigh-Anne Dell
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, 50312
| | - Mads F Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, 2000, Fredericksberg, Denmark
| | - Jerome M Siegel
- Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Veterans Administration Sepulveda Ambulatory Medical Center, North Hills, California, 91343
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
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23
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Infrasonic and Seismic Communication in the Vertebrates with Special Emphasis on the Afrotheria: An Update and Future Directions. VERTEBRATE SOUND PRODUCTION AND ACOUSTIC COMMUNICATION 2016. [DOI: 10.1007/978-3-319-27721-9_7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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The Evolution of Brains and Cognitive Abilities. Evol Biol 2016. [DOI: 10.1007/978-3-319-41324-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Dell LA, Karlsson KA, Patzke N, Spocter MA, Siegel JM, Manger PR. Organization of the sleep-related neural systems in the brain of the minke whale (Balaenoptera acutorostrata). J Comp Neurol 2015; 524:2018-35. [PMID: 26588800 DOI: 10.1002/cne.23931] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 12/12/2022]
Abstract
The current study analyzed the nuclear organization of the neural systems related to the control and regulation of sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the minke whale, a mysticete cetacean. While odontocete cetaceans sleep in an unusual manner, with unihemispheric slow wave sleep (USWS) and suppressed REM sleep, it is unclear whether the mysticete whales show a similar sleep pattern. Previously, we detailed a range of features in the odontocete brain that appear to be related to odontocete-type sleep, and here present our analysis of these features in the minke whale brain. All neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals and the harbor porpoise were present in the minke whale, with no specific nuclei being absent, and no novel nuclei being present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic and orexinergic systems, and the GABAergic elements of these nuclei. Quantitative analysis revealed that the numbers of pontine cholinergic (274,242) and noradrenergic (203,686) neurons, and hypothalamic orexinergic neurons (277,604), are markedly higher than other large-brained bihemispheric sleeping mammals. Small telencephalic commissures (anterior, corpus callosum, and hippocampal), an enlarged posterior commissure, supernumerary pontine cholinergic and noradrenergic cells, and an enlarged peripheral division of the dorsal raphe nuclear complex of the minke whale, all indicate that the suite of neural characteristics thought to be involved in the control of USWS and the suppression of REM in the odontocete cetaceans are present in the minke whale. J. Comp. Neurol. 524:2018-2035, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Leigh-Anne Dell
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Karl Ae Karlsson
- Biomedical Engineering, Reykjavik University, Reykjavik, Iceland
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, USA
| | - Jerome M Siegel
- Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Sepulveda VAMC, North Hills, California, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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Kharlamova AS, Saveliev SV, Protopopov AV, Maseko BC, Bhagwandin A, Manger PR. The mummified brain of a pleistocene woolly mammoth (Mammuthus primigenius) compared with the brain of the extant African elephant (Loxodonta africana). J Comp Neurol 2015; 523:2326-43. [PMID: 26011110 DOI: 10.1002/cne.23817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/14/2015] [Accepted: 05/14/2015] [Indexed: 11/11/2022]
Abstract
This study presents the results of an examination of the mummified brain of a pleistocene woolly mammoth (Mammuthus primigenius) recovered from the Yakutian permafrost in Siberia, Russia. This unique specimen (from 39,440-38,850 years BP) provides the rare opportunity to compare the brain morphology of this extinct species with a related extant species, the African elephant (Loxodonta africana). An anatomical description of the preserved brain of the woolly mammoth is provided, along with a series of quantitative analyses of various brain structures. These descriptions are based on visual inspection of the actual specimen as well as qualitative and quantitative comparison of computed tomography imaging data obtained for the woolly mammoth in comparison with magnetic resonance imaging data from three African elephant brains. In general, the brain of the woolly mammoth specimen examined, estimated to weigh between 4,230 and 4,340 g, showed the typical shape, size, and gross structures observed in extant elephants. Quantitative comparative analyses of various features of the brain, such as the amygdala, corpus callosum, cerebellum, and gyrnecephalic index, all indicate that the brain of the woolly mammoth specimen examined has many similarities with that of modern African elephants. The analysis provided here indicates that a specific brain type representative of the Elephantidae is likely to be a feature of this mammalian family. In addition, the extensive similarities between the woolly mammoth brain and the African elephant brain indicate that the specializations observed in the extant elephant brain are likely to have been present in the woolly mammoth.
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Affiliation(s)
| | | | - Albert V Protopopov
- Academy of Sciences of the Sakha Republic (Yakutia), Yakutsk, Sakha Republic (Yakutia), 677007, Russia
| | - Busisiwe C Maseko
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
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Raghanti MA, Todd N, Hof PR. Probing the proboscidea: Lessons from the past. J Comp Neurol 2015; 523:2321-5. [PMID: 26184071 DOI: 10.1002/cne.23824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio, 44242
| | - Nancy Todd
- Biology and Environmental Studies, Manhattanville College, Purchase, New York, 10577
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029.,New York Consortium in Evolutionary Primatology, New York, New York, 10029
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Stoeger AS, Manger P. Vocal learning in elephants: neural bases and adaptive context. Curr Opin Neurobiol 2014; 28:101-7. [PMID: 25062469 PMCID: PMC4181794 DOI: 10.1016/j.conb.2014.07.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 06/28/2014] [Accepted: 07/01/2014] [Indexed: 10/28/2022]
Abstract
In the last decade clear evidence has accumulated that elephants are capable of vocal production learning. Examples of vocal imitation are documented in African (Loxodonta africana) and Asian (Elephas maximus) elephants, but little is known about the function of vocal learning within the natural communication systems of either species. We are also just starting to identify the neural basis of elephant vocalizations. The African elephant diencephalon and brainstem possess specializations related to aspects of neural information processing in the motor system (affecting the timing and learning of trunk movements) and the auditory and vocalization system. Comparative interdisciplinary (from behavioral to neuroanatomical) studies are strongly warranted to increase our understanding of both vocal learning and vocal behavior in elephants.
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Affiliation(s)
- Angela S Stoeger
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
| | - Paul Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Barton R, Venditti C. Rapid Evolution of the Cerebellum in Humans and Other Great Apes. Curr Biol 2014; 24:2440-4. [DOI: 10.1016/j.cub.2014.08.056] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 07/16/2014] [Accepted: 08/22/2014] [Indexed: 10/24/2022]
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Herculano-Houzel S, Manger PR, Kaas JH. Brain scaling in mammalian evolution as a consequence of concerted and mosaic changes in numbers of neurons and average neuronal cell size. Front Neuroanat 2014; 8:77. [PMID: 25157220 PMCID: PMC4127475 DOI: 10.3389/fnana.2014.00077] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/21/2014] [Indexed: 11/29/2022] Open
Abstract
Enough species have now been subject to systematic quantitative analysis of the relationship between the morphology and cellular composition of their brain that patterns begin to emerge and shed light on the evolutionary path that led to mammalian brain diversity. Based on an analysis of the shared and clade-specific characteristics of 41 modern mammalian species in 6 clades, and in light of the phylogenetic relationships among them, here we propose that ancestral mammal brains were composed and scaled in their cellular composition like modern afrotherian and glire brains: with an addition of neurons that is accompanied by a decrease in neuronal density and very little modification in glial cell density, implying a significant increase in average neuronal cell size in larger brains, and the allocation of approximately 2 neurons in the cerebral cortex and 8 neurons in the cerebellum for every neuron allocated to the rest of brain. We also propose that in some clades the scaling of different brain structures has diverged away from the common ancestral layout through clade-specific (or clade-defining) changes in how average neuronal cell mass relates to numbers of neurons in each structure, and how numbers of neurons are differentially allocated to each structure relative to the number of neurons in the rest of brain. Thus, the evolutionary expansion of mammalian brains has involved both concerted and mosaic patterns of scaling across structures. This is, to our knowledge, the first mechanistic model that explains the generation of brains large and small in mammalian evolution, and it opens up new horizons for seeking the cellular pathways and genes involved in brain evolution.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Neurociência Translacional, Ministério de Ciência e Tecnologia São Paulo, Brazil
| | - Paul R Manger
- Department of Anatomy, University of the Witwatersrand Johannesburg, South Africa
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University Nashville, TN, USA
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Herculano-Houzel S, Avelino-de-Souza K, Neves K, Porfírio J, Messeder D, Mattos Feijó L, Maldonado J, Manger PR. The elephant brain in numbers. Front Neuroanat 2014; 8:46. [PMID: 24971054 PMCID: PMC4053853 DOI: 10.3389/fnana.2014.00046] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/27/2014] [Indexed: 11/13/2022] Open
Abstract
What explains the superior cognitive abilities of the human brain compared to other, larger brains? Here we investigate the possibility that the human brain has a larger number of neurons than even larger brains by determining the cellular composition of the brain of the African elephant. We find that the African elephant brain, which is about three times larger than the human brain, contains 257 billion (10(9)) neurons, three times more than the average human brain; however, 97.5% of the neurons in the elephant brain (251 billion) are found in the cerebellum. This makes the elephant an outlier in regard to the number of cerebellar neurons compared to other mammals, which might be related to sensorimotor specializations. In contrast, the elephant cerebral cortex, which has twice the mass of the human cerebral cortex, holds only 5.6 billion neurons, about one third of the number of neurons found in the human cerebral cortex. This finding supports the hypothesis that the larger absolute number of neurons in the human cerebral cortex (but not in the whole brain) is correlated with the superior cognitive abilities of humans compared to elephants and other large-brained mammals.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | - Kamilla Avelino-de-Souza
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | - Kleber Neves
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | - Jairo Porfírio
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | - Débora Messeder
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | - Larissa Mattos Feijó
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
- Instituto Nacional de Neurociência TranslacionalSão Paulo, Brazil
| | | | - Paul R. Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburg, South Africa
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Ridgway SH, Hanson AC. Sperm Whales and Killer Whales with the Largest Brains of All Toothed Whales Show Extreme Differences in Cerebellum. BRAIN, BEHAVIOR AND EVOLUTION 2014; 83:266-74. [DOI: 10.1159/000360519] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 09/16/2013] [Indexed: 11/19/2022]
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Jacobs B, Johnson NL, Wahl D, Schall M, Maseko BC, Lewandowski A, Raghanti MA, Wicinski B, Butti C, Hopkins WD, Bertelsen MF, Walsh T, Roberts JR, Reep RL, Hof PR, Sherwood CC, Manger PR. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates. Front Neuroanat 2014; 8:24. [PMID: 24795574 PMCID: PMC4005950 DOI: 10.3389/fnana.2014.00024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/01/2014] [Indexed: 11/13/2022] Open
Abstract
Although the basic morphological characteristics of neurons in the cerebellar cortex have been documented in several species, virtually nothing is known about the quantitative morphological characteristics of these neurons across different taxa. To that end, the present study investigated cerebellar neuronal morphology among eight different, large-brained mammalian species comprising a broad phylogenetic range: afrotherians (African elephant, Florida manatee), carnivores (Siberian tiger, clouded leopard), cetartiodactyls (humpback whale, giraffe) and primates (human, common chimpanzee). Specifically, several neuron types (e.g., stellate, basket, Lugaro, Golgi, and granule neurons; N = 317) of the cerebellar cortex were stained with a modified rapid Golgi technique and quantified on a computer-assisted microscopy system. There was a 64-fold variation in brain mass across species in our sample (from clouded leopard to the elephant) and a 103-fold variation in cerebellar volume. Most dendritic measures tended to increase with cerebellar volume. The cerebellar cortex in these species exhibited the trilaminate pattern common to all mammals. Morphologically, neuron types in the cerebellar cortex were generally consistent with those described in primates (Fox et al., 1967) and rodents (Palay and Chan-Palay, 1974), although there was substantial quantitative variation across species. In particular, Lugaro neurons in the elephant appeared to be disproportionately larger than those in other species. To explore potential quantitative differences in dendritic measures across species, MARSplines analyses were used to evaluate whether species could be differentiated from each other based on dendritic characteristics alone. Results of these analyses indicated that there were significant differences among all species in dendritic measures.
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Affiliation(s)
- Bob Jacobs
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado CollegeColorado Springs, CO, USA
| | - Nicholas L. Johnson
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado CollegeColorado Springs, CO, USA
| | - Devin Wahl
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado CollegeColorado Springs, CO, USA
| | - Matthew Schall
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado CollegeColorado Springs, CO, USA
| | - Busisiwe C. Maseko
- Faculty of Health Sciences, School of Anatomical Sciences, University of the WitwatersrandJohannesburg, South Africa
| | | | | | - Bridget Wicinski
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount SinaiNew York, NY, USA
| | - Camilla Butti
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount SinaiNew York, NY, USA
| | - William D. Hopkins
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research CenterAtlanta, GA, USA
| | - Mads F. Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen ZooFrederiksberg, Denmark
| | - Timothy Walsh
- Smithsonian National Zoological ParkWashington, DC, USA
| | | | - Roger L. Reep
- Department of Physiological Sciences, University of FloridaGainesville, FL, USA
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount SinaiNew York, NY, USA
| | - Chet C. Sherwood
- Department of Anthropology, The George Washington UniversityWashington, DC, USA
| | - Paul R. Manger
- Faculty of Health Sciences, School of Anatomical Sciences, University of the WitwatersrandJohannesburg, South Africa
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Neves K, Ferreira FM, Tovar-Moll F, Gravett N, Bennett NC, Kaswera C, Gilissen E, Manger PR, Herculano-Houzel S. Cellular scaling rules for the brain of afrotherians. Front Neuroanat 2014; 8:5. [PMID: 24596544 PMCID: PMC3925844 DOI: 10.3389/fnana.2014.00005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 01/27/2014] [Indexed: 12/05/2022] Open
Abstract
Quantitative analysis of the cellular composition of rodent, primate and eulipotyphlan brains has shown that non-neuronal scaling rules are similar across these mammalian orders that diverged about 95 million years ago, and therefore appear to be conserved in evolution, while neuronal scaling rules appear to be free to vary in evolution in a clade-specific manner. Here we analyze the cellular scaling rules that apply to the brain of afrotherians, believed to be the first clade to radiate from the common eutherian ancestor. We find that afrotherians share non-neuronal scaling rules with rodents, primates and eulipotyphlans, as well as the coordinated scaling of numbers of neurons in the cerebral cortex and cerebellum. Afrotherians share with rodents and eulipotyphlans, but not with primates, the scaling of number of neurons in the cortex and in the cerebellum as a function of the number of neurons in the rest of the brain. Afrotheria also share with rodents and eulipotyphlans the neuronal scaling rules that apply to the cerebral cortex. Afrotherians share with rodents, but not with eulipotyphlans nor primates, the neuronal scaling rules that apply to the cerebellum. Importantly, the scaling of the folding index of the cerebral cortex with the number of neurons in the cerebral cortex is not shared by either afrotherians, rodents, or primates. The sharing of some neuronal scaling rules between afrotherians and rodents, and of some additional features with eulipotyphlans and primates, raise the interesting possibility that these shared characteristics applied to the common eutherian ancestor. In turn, the clade-specific characteristics that relate to the distribution of neurons along the surface of the cerebral cortex and to its degree of gyrification suggest that these characteristics compose an evolutionarily plastic suite of features that may have defined and distinguished mammalian groups in evolution.
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Affiliation(s)
- Kleber Neves
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brasil ; Instituto Nacional de Neurociência Translacional, CNPq/MCT São Paulo, Brasil
| | - Fernanda M Ferreira
- D'Or Institute for Research and Education (IDOR) Rio de Janeiro, Brasil ; Bioimaging National Center, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
| | - Fernanda Tovar-Moll
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brasil ; Instituto Nacional de Neurociência Translacional, CNPq/MCT São Paulo, Brasil ; D'Or Institute for Research and Education (IDOR) Rio de Janeiro, Brasil ; Bioimaging National Center, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
| | - Nadine Gravett
- Department of Zoology and Entomology, University of Pretoria Pretoria, South Africa
| | - Nigel C Bennett
- Faculté des Sciences, University of Kisangani Kisangani, Democratic Republic of Congo
| | - Consolate Kaswera
- Department of African Zoology, Royal Museum for Central Africa Tervuren, Belgium
| | - Emmanuel Gilissen
- Laboratory of Histology and Neuropathology, Université Libre de Bruxelles Brussels, Belgium ; Department of Anthropology, University of Arkansas Fayetteville, AR, USA
| | - Paul R Manger
- School of Anatomical Sciences, University of the Witwatersrand Johannesburg, South Africa
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brasil ; Instituto Nacional de Neurociência Translacional, CNPq/MCT São Paulo, Brasil
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Butti C, Ewan Fordyce R, Ann Raghanti M, Gu X, Bonar CJ, Wicinski BA, Wong EW, Roman J, Brake A, Eaves E, Spocter MA, Tang CY, Jacobs B, Sherwood CC, Hof PR. The cerebral cortex of the pygmy hippopotamus, Hexaprotodon liberiensis (Cetartiodactyla, Hippopotamidae): MRI, cytoarchitecture, and neuronal morphology. Anat Rec (Hoboken) 2014; 297:670-700. [PMID: 24474726 DOI: 10.1002/ar.22875] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 11/04/2013] [Indexed: 12/24/2022]
Abstract
The structure of the hippopotamus brain is virtually unknown because few studies have examined more than its external morphology. In view of their semiaquatic lifestyle and phylogenetic relatedness to cetaceans, the brain of hippopotamuses represents a unique opportunity for better understanding the selective pressures that have shaped the organization of the brain during the evolutionary process of adaptation to an aquatic environment. Here we examined the histology of the cerebral cortex of the pygmy hippopotamus (Hexaprotodon liberiensis) by means of Nissl, Golgi, and calretinin (CR) immunostaining, and provide a magnetic resonance imaging (MRI) structural and volumetric dataset of the anatomy of its brain. We calculated the corpus callosum area/brain mass ratio (CCA/BM), the gyrencephalic index (GI), the cerebellar quotient (CQ), and the cerebellar index (CI). Results indicate that the cortex of H. liberiensis shares one feature exclusively with cetaceans (the lack of layer IV across the entire cerebral cortex), other features exclusively with artiodactyls (e.g., the morphologiy of CR-immunoreactive multipolar neurons in deep cortical layers, gyrencephalic index values, hippocampus and cerebellum volumetrics), and others with at least some species of cetartiodactyls (e.g., the presence of a thick layer I, the pattern of distribution of CR-immunoreactive neurons, the presence of von Economo neurons, clustering of layer II in the occipital cortex). The present study thus provides a comprehensive dataset of the neuroanatomy of H. liberiensis that sets the ground for future comparative studies including the larger Hippopotamus amphibius.
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Affiliation(s)
- Camilla Butti
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
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Cozzi B, Povinelli M, Ballarin C, Granato A. The brain of the horse: weight and cephalization quotients. BRAIN, BEHAVIOR AND EVOLUTION 2013; 83:9-16. [PMID: 24335261 DOI: 10.1159/000356527] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/18/2013] [Indexed: 11/19/2022]
Abstract
The horse is a common domestic animal whose anatomy has been studied since the XVI century. However, a modern neuroanatomy of this species does not exist and most of the data utilized in textbooks and reviews derive from single specimens or relatively old literature. Here, we report information on the brain of Equus caballus obtained by sampling 131 horses, including brain weight (as a whole and subdivided into its constituents), encephalization quotient (EQ), and cerebellar quotient (CQ), and comparisons with what is known about other relevant species. The mean weight of the fresh brains in our experimental series was 598.63 g (SEM ± 7.65), with a mean body weight of 514.12 kg (SEM ± 15.42). The EQ was 0.78 and the CQ was 0.841. The data we obtained indicate that the horse possesses a large, convoluted brain, with a weight similar to that of other hoofed species of like mass. However, the shape of the brain, the noteworthy folding of the neocortex, and the peculiar longitudinal distribution of the gyri suggest an evolutionary specificity at least partially separate from that of the Cetartiodactyla (even-toed mammals and cetaceans) with whom Perissodactyla (odd-toed mammals) are often grouped.
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Affiliation(s)
- Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
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Maseko BC, Patzke N, Fuxe K, Manger PR. Architectural Organization of the African Elephant Diencephalon and Brainstem. BRAIN, BEHAVIOR AND EVOLUTION 2013; 82:83-128. [DOI: 10.1159/000352004] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/03/2013] [Indexed: 11/19/2022]
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38
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Manger PR, Spocter MA, Patzke N. The evolutions of large brain size in mammals: the 'over-700-gram club quartet'. BRAIN, BEHAVIOR AND EVOLUTION 2013; 82:68-78. [PMID: 23979457 DOI: 10.1159/000352056] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The current paper details our developing understanding of the evolution of large brains in mammals. In order to do this, we first define brains that we consider to be large--those that have passed the apparent 700-gram ceiling on brain mass evolution in the class Mammalia. The over-700-gram club includes certain species within the genus Homo, order Cetacea, order Proboscidea, and suborder Pinnipedia. Our analysis suggests that selection for body size appears to be the most important factor in the evolution of large brain size, but there also appear to be internal morphophysiological constraints on large brain size evolution that need to be overcome in order for brains to break the 700-gram barrier. These two aspects appear to be common themes in the evolution of large brains. This significantly diminishes the explanatory value of selection for greater cognitive capacities as a principal factor in the evolution of enlarged brain sizes above the 700-gram threshold.
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Affiliation(s)
- Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.
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39
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Maseko BC, Jacobs B, Spocter MA, Sherwood CC, Hof PR, Manger PR. Qualitative and Quantitative Aspects of the Microanatomy of the African Elephant Cerebellar Cortex. BRAIN, BEHAVIOR AND EVOLUTION 2013; 81:40-55. [DOI: 10.1159/000345565] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 09/14/2012] [Indexed: 11/19/2022]
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