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| A series of horizontal structural MR images through the brain of the black rhinoceros (D. bicornis). (A) is the most ventral section and (H) is the most dorsal section, with each section having a thickness of 2 mm and each section being 6 mm apart. Note the typically mammalian topography of the various regions and structures of the brain. Scale bar = 1 cm. Amyg, amygdaloid body; C, caudate nucleus; Cb, cerebellum; DT, dorsal thalamus; Hip, hippocampus; Hyp, hypothalamus; IC, inferior colliculus; LV, lateral ventricle; NEO, neocortex; Olf. Tub, olfactory tubercle; P, putamen; PC, cerebral peduncle; Pir, piriform cortex; SC, superior colliculus.
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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 descr...
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Context 1
... does not appear to be any specifically distinct sulci or gyri that can be conclusively compared to those present in other species, even closely related species such as horses. In addition, our MR images did not assist in the determination of specific sulci and gyri, as many of the sulci are quite deep and do not appear to have enough continuity to allow a specific nomenclature to be applied to them for comparison (Figures 3-6). In order to avoid confusion, and the potential incorrect assignation of associated functional regions, we have thus not named the sulci and gyri present in the neocortex of the rhinoceros, which was also avoided in earlier descriptions of the brains of other rhinoceros species (Owen, 1850;Garrod, 1878;Beddard and Treves, 1887). ...
Context 2
... MR images reveal substantial detail regarding the internal organization of the brains of both species of rhinoceros and, as for the external surface of the brain, the organization of the internal aspects of the brain revealed with MR imaging are similar between the two species (Figures 3-6). Due to this similarity, the following description applies to both species unless otherwise stated. ...
Context 3
... lateral ventricles occupied a position typical of mammals within the telencephalon, having a frontal horn (connected to the olfactory ventricle), a body overlying the corpus striatum and diencephalon, a small temporal horn dorsal to the hippocampal formation in the temporal lobe, but no clear occipital horn could be observed. The ventricles of the white rhinoceros appear somewhat larger than those of the black rhinoceros (Figures 3-6). ...
Citations
... In this context, post-mortem MRI data are important because they share common signal forming mechanisms with in vivo MRI and a common tissue state with microscopy, providing a framework for investigation across multiple spatial scales. Post-mortem MRI facilitates comparative anatomy investigations in species that are not traditionally accessible for in vivo imaging (Berns et al., 2015;Bhagwandin et al., 2017;Grewal et al., 2020;Heuer et al., 2019), including extinct species (Berns and Ashwell, 2017). Long post-mortem scans provide the opportunity to push the boundaries of spatial resolution, providing whole human brain coverage reaching voxel sizes of 100-500 μm (Edlow et al., 2019;Foxley et al., 2016;Fritz et al., 2019;Weigel et al., 2021), edging closer to microscopy techniques but benefitting from compatibility with in vivo imaging. ...
... (a) displays diffusion tensor principal diffusion direction maps (modulated by fractional anisotropy). characterize macroscopic brain structure, long-range structural connectivity, and tissue microstructure in species that are not traditional experimental models, and in particular rare species where very few brain samples may be available (Berns and Ashwell, 2017;Bhagwandin et al., 2017;Grewal et al., 2020;Mars et al., 2014). ...
Post-mortem MRI provides the opportunity to acquire high-resolution datasets to investigate neuroanatomy, and validate the origins of image contrast through microscopy comparisons. We introduce the Digital Brain Bank (open.win.ox.ac.uk/DigitalBrainBank), a data release platform providing open access to curated, multimodal post-mortem neuroimaging datasets. Datasets span three themes - Digital Neuroanatomist : datasets for detailed neuroanatomical investigations; Digital Brain Zoo : datasets for comparative neuroanatomy; Digital Pathologist : datasets for neuropathology investigations. The first Digital Brain Bank release includes twenty one distinctive whole-brain diffusion MRI datasets for structural connectivity investigations, alongside microscopy and complementary MRI modalities. This includes one of the highest-resolution whole-brain human diffusion MRI datasets ever acquired, whole-brain diffusion MRI in fourteen non-human primate species, and one of the largest post-mortem whole-brain cohort imaging studies in neurodegeneration. The Digital Brain Bank is the culmination of our lab's investment into post-mortem MRI methodology and MRI-microscopy analysis techniques. This manuscript provides a detailed overview of our work with post-mortem imaging to date, including the development of diffusion MRI methods to image large post-mortem samples, including whole, human brains. Taken together, the Digital Brain Bank provides cross-scale, cross-species datasets facilitating the incorporation of post-mortem data into neuroimaging studies.
... Indeed, paranasal sinuses and even more brain endocasts are related to several morphofunctional and eco-ethological aspects, and therefore are widely investigated for inferring these characteristics in extinct species (Sakai et al. 2011;Vinuesa et al. 2016;Iurino et al. 2020;Pérez-Ramos et al. 2020;Boscaini et al. 2020a). In a recent work (Bhagwandin et al. 2017), the differences in brain morphology of the extant rhinoceros Diceros bicornis (Linnaeus, 1758) and Ceratotherium simum (Burchell, 1817) have been related to diet. According to the authors, the shape of the brains reflects the overall architecture of the skulls, which in turn is related to the behaviour and feeding habits of the two species, browsing for the black rhinoceros, and grazing for the white rhinoceros (Bhagwandin et al. 2017). ...
... In a recent work (Bhagwandin et al. 2017), the differences in brain morphology of the extant rhinoceros Diceros bicornis (Linnaeus, 1758) and Ceratotherium simum (Burchell, 1817) have been related to diet. According to the authors, the shape of the brains reflects the overall architecture of the skulls, which in turn is related to the behaviour and feeding habits of the two species, browsing for the black rhinoceros, and grazing for the white rhinoceros (Bhagwandin et al. 2017). More recently, Iurino et al. (2020) using CT analyses, confirmed the morphological differences in the brain endocasts of D. bicornis and C. simum, and documented a similar arrangement of the cranial pneumatisation in both species. ...
Suidae remains recovered from the late Pliocene site of Collepardo (Latium, central Italy) are described and assigned to Sus arvernensis, a small-sized Ruscinian to Early Villafranchian (MN14-MN16a) species. In Italy, S. arvernensis only occurs in the Triversa Faunal Unit (MN16a), supporting the recently revised chronology of Collepardo. CT-scan methods are used to virtually extract and analyse a newly discovered neurocranium, providing the content for the first inner cranial description carried out on an extinct Suidae. Our analysis reveals that S. arvernensis has an anteroposteriorly elongated and dorsoventrally flat cerebrum, similar to that of the Asian Babyrousa babyrussa and the African Hylochoerus meinertzhageni. These species substantially differ in size and are representatives of two widely diverging phylogenetic clades, excluding relatively simple evolutionary or allometric explanations for brain morphology in Suidae.
... In this context, post-mortem MRI data are important because they share common signal forming mechanisms with in vivo MRI and a common tissue state with microscopy, providing a framework for investigation across multiple spatial scales. Postmortem MRI facilitates comparative anatomy investigations in species that are not traditionally accessible for in-vivo imaging (Berns et al., 2015;Bhagwandin, Haagensen, & Manger, 2017;Grewal et al., 2020;Heuer et al., 2019), including extinct species (Berns & Ashwell, 2017). Long post-mortem scans provide the opportunity to push the boundaries of spatial resolution, providing whole human brain coverage reaching voxel sizes of 100-500 μm (Edlow et al., 2019;Foxley et al., 2016;Fritz et al., 2019;Weigel et al., 2021), edging closer to microscopy techniques but benefitting from compatibility with in-vivo imaging. ...
... Third, MRI investigations can be performed in whole brain samples, rather than excised tissue sections. This makes post-mortem MRI ideally placed to characterise macroscopic brain structure, long-range structural connectivity and tissue microstructure in species that are not traditional experimental models, and in particular rare species where very few brain samples may be available (Berns & Ashwell, 2017;Bhagwandin et al., 2017;Grewal et al., 2020;Mars et al., 2014). ...
Post-mortem MRI provides the opportunity to acquire high-resolution datasets to investigate neuroanatomy, and validate the origins of image contrast through microscopy comparisons. We introduce the Digital Brain Bank (open.win.ox.ac.uk/DigitalBrainBank), an interactive data discovery and release platform providing open access to curated, multimodal post-mortem neuroimaging datasets. Datasets span three themes - Digital Neuroanatomist: data for neuroanatomical investigations; Digital Brain Zoo: data for comparative neuroanatomy; Digital Pathologist: data for neuropathology investigations. The first Digital Brain Bank release includes fourteen distinctive whole-brain diffusion MRI datasets for structural connectivity investigations, alongside microscopy and complementary MRI modalities. This includes one of the highest-resolution whole-brain human diffusion MRI datasets ever acquired, whole-brain diffusion MRI in seven non-human primate species, and one of the largest post-mortem whole-brain cohort imaging studies in neurodegeneration. Taken together, the Digital Brain Bank provides a cross-scale, cross-species investigation framework facilitating the incorporation of post-mortem data into neuroimaging studies.
... For this, we curated published GI values for each genus; any species in a genus with a GI value above 1.2 was considered gyrencephalic (Figures 6A-C). When GI values were not available, brain image data from the Comparative Mammalian Brain Collection and published statements describing species as gyrencephalic or lissencephalic were used for this classification (Harper and Maser, 1976;Sullivan, 1982;Kawamoto et al., 1998;Phelps and Young, 2003;Xiao et al., 2006;Marino, 2007;Morawski et al., 2010;Lewitus et al., 2013;Zilles et al., 2013;Mota and Herculano-Houzel, 2015;Bhagwandin et al., 2017;Spocter et al., 2017;Raghanti et al., 2018;Ashwell and Gurovich, 2019;Marchand and Schwartz, 2019). The collection available at 2 was used in our binary classification system. ...
An expanded cortex is a hallmark of human neurodevelopment and endows increased cognitive capabilities. Recent work has shown that the cell cycle-related gene NDE1 is essential for proper cortical development. Patients who have mutations in NDE1 exhibit congenital microcephaly as a primary phenotype. At the cellular level, NDE1 is essential for interkinetic nuclear migration and mitosis of radial glial cells, which translates to an indispensable role in neurodevelopment. The nuclear migration function of NDE1 is well conserved across Opisthokonta. In mammals, multiple isoforms containing alternate terminal exons, which influence the functionality of NDE1, have been reported. It has been noted that the pattern of terminal exon usage mirrors patterns of cortical complexity in mammals. To provide context to these findings, here, we provide a comprehensive review of the literature regarding NDE1, its molecular biology and physiological relevance at the cellular and organismal levels. In particular, we outline the potential roles of NDE1 in progenitor cell behavior and explore the spectrum of NDE1 pathogenic variants. Moreover, we assessed the evolutionary conservation of NDE1 and interrogated whether the usage of alternative terminal exons is characteristic of species with gyrencephalic cortices. We found that gyrencephalic species are more likely to express transcripts that use the human-associated terminal exon, whereas lissencephalic species tend to express transcripts that use the mouse-associated terminal exon. Among gyrencephalic species, the human-associated terminal exon was preferentially expressed by those with a high order of gyrification. These findings underscore phylogenetic relationships between the preferential usage of NDE1 terminal exon and high-order gyrification, which provide insight into cortical evolution underlying high-order brain functions.
... Probably due to technical difficulties in performing CT scans on bulk and large skulls with conventional medical equipment. Consequently, many developmental and morpho-functional aspects of the skull pneumatization and the brain morphology are still almost completely unknown in extinct and extant rhinoceroses (Garrod, 1878;Bhagwandin et al., 2017). The most comprehensive ontogenetic studies on fossil Rhinocerotinae, based on external craniodental features, were conducted on Chilotherium wimani with nine complete skulls from the Late Miocene of China (Deng, 2001b), on Teleoceras major represented by 27 skulls from the Miocene of Nebraska (Hagge, 2010) and probably the largest sample of 399 mandibular fragments and limb bones from a minimum of 42 individuals of C. antiquitatis was reported by Shpansky (2014) from two Late Pleistocene sites in the Tomsk Priob'e area (south-east Western Siberia). ...
... Therefore, the MPND1083 represents one a few natural brain endocasts described in extinct Rhinocerotinae (Figure 6). MPND1083 consists of a globular telencephalon, free of convolutions with the frontal lobes less expanded than the parietal ones resembling in the general shape those reported on extant Ceratotherium simum and Dicerorhinus sumatrensis (Garrod, 1878;Bhagwandin et al., 2017), whereas it differs from that of Diceros bicornis ( Figure 5I). In dorsal view, the brain of the black rhino shows a very rounded shape without the narrowing at the level of the lateral sulcus, which is evident in the other taxa. ...
... In dorsal view, the brain of the black rhino shows a very rounded shape without the narrowing at the level of the lateral sulcus, which is evident in the other taxa. The different brain morphology of extant D. bicornis and C. simum (Figures 5I,J) has been studied with Magnetic Resonance Imaging by Bhagwandin et al. (2017) and related to diet. According to the authors, the shape of the brains reflects the overall architecture of the skulls, which in turn are related to the feeding habits of the two species, browsing for the black rhinoceros and grazing for the white rhinoceros. ...
Cranial remains of juvenile fossil rhinoceroses are rarely described in literature and very few is known about the ontogenetic development of their inner anatomy. In this study, we report the first CT based description of a juvenile braincase and its natural brain endocast of a late Middle Pleistocene Rhinocerotinae from Melpignano (Apulia, Italy). The specimen belongs to an individual about 12–18 months old, representing to date the youngest Pleistocene rhinoceros of Mediterranean Europe documented by neurocranial material. Through digital visualization methods the neurocranium has been restored and the anatomy of both the brain and the paranasal sinuses has been obtained and compared with those of juvenile and adult Pleistocene rhinoceroses. We evidence a different morphological development of the inner cranial anatomy in fossil and extant African species.
... 24 Advances in Anthropology tion of an exposed, environmentally sensitive skin and a large brain might have played a key role during animal evolution. Several terrestrial mammals are largely hairless, including the hippopotamus, elephant, rhinoceros and naked mole rat, and the hippopotamus and rhinoceros do not have large brains (Lyras, 2018;Bhagwandin et al., 2017). We propose that because these two animals have thick skin, it might have been difficult to construct tightly-organized, arborizing peripheral nerve networks in their skin. ...
Among terrestrial mammals, Homo sapiens has evolved a very specific anatomical feature-very little body hair-thus, the skin surface is exposed directly to the environment. We and others have demonstrated that skin epi-thelial cells, called keratinocytes, express not only functional sensory systems for a variety of environmental responses, but also a series of neurotransmitter receptors that play key roles in information processing in the brain. Furthermore , the brain cortex is particularly large in Homo sapiens, which has a higher ratio of brain to whole-body weight than any other mammalian species. Here we propose that the evolutionary success and global spread of Ho-mo sapiens are due at least in part to the existence and interaction of these two systems; i.e. the epidermis and brain cortex. First, we discuss the role of the epidermis as a sophisticated organ with multiple sensory inputs and information processing capabilities, and then we consider the putative requirement for a large brain to carry out simulations and predictions based on input from multiple epidermal systems. We also present some other examples where a functionally sophisticated epidermis is associated with a large brain size. Finally, we discuss possible reasons why Homo sapiens has emerged as the sole surviving human subspecies.
... Along that line, substantial progress is noted in the study of brain structure in gyrencephalic species beyond primates, such as the dromedary (Simon, 1965), llama (Welker et al., 1976), horse (Cozzi et al., 2014), hippopotamus (Butti et al., 2014), rhinoceros (Manger, 2011;Bhagwandin et al., 2017), elephant seal, and sea lion (Sawyer et al., 2016;Turner et al., 2017), not to mention the extensive literature on proboscidea (Dexler, 1907;Jakob, 1909;Janssen and Stephan, 1956;Haug, 1966;Cozzi et al., 2001;Shoshani et al., 2006;Jacobs et al., 2011;Herculano-Houzel et al., 2014) and cetacea (Tower, 1954;Haug, 1970;Walløe et al., 2010;Butti et al., 2011;Mortensen et al., 2014). ...
Over the last two decades, neuroscience has witnessed an explosion in the utilization of non-invasive imaging methods (particularly MRI) that are used to investigate to study the brain. Providing accurate and detailed imaging, MRI has a significant impact in figuring out the neuroanatomy and functioning of the brain. In recent years, researchers studying on veterinary science have seen MRI an indispensable tool for themselves. It is essential to understand the anatomy of the normal brain in order to explain many of the pathological processes. This review focused on neuroanatomical studies, atlases and templates generated from the brains of domestic animals (cat, dog, pig, horse, donkey, cattle, sheep, goat, camel) using MRI from the 1980s to the present. Its data were summarized under three main parts. Firstly, the cross-sectional anatomy of the brain created using MRI was examined. Afterwards, digital atlases and templates, which have had an essential place in modern neuroimaging analysis (such as registration, segmentation and three-dimensional reconstruction) in recent years, were summarized. Finally, in vivo or ex vivo studies in which crucial white matter tracts in the brain are three-dimensionally modeled with DTI (Diffusion Tensor Imaging) in domestic animals were reviewed. Several studies examining the neocortex by DTI were also included in the review in this section. There were also neuroanatomy studies conducted with MRI in the several specific species in this review. MRI is one of the most successful imaging techniques known for non-invasive, high-resolution brain imaging in neuroimaging. The aim of this study is to guide researchers studying in veterinary science to investigate the brain of domestic animals with MRI.
