Comparative anatomy of the caudate nucleus in canids and felids: Associations with brain size, curvature, cross-sectional properties, and behavioral ecology.

The evolutionary history of canids and felids is marked by a deep time separation that has uniquely shaped their behavior and phenotype toward refined predatory abilities. The caudate nucleus is a subcortical brain structure associated with both motor control and cognitive, emotional, and executive functions. We used a combination of three-dimensional imaging, allometric scaling, and structural analyses to compare the size and shape characteristics of the caudate nucleus.

Nuclear parcellation and numbers of orexinergic neurons in five species of larger brained birds.

The orexinergic/hypocretinergic system, while having several roles, appears to be a key link in the balance between arousal and food intake. In birds, to date, this system has only been examined anatomically in four species, all with brains smaller than 3.5 g and of limited phylogenetic range.

Neuropil Variation in the Prefrontal, Motor, and Visual Cortex of Six Felids.

Introduction: Felids have evolved a specialized suite of morphological adaptations for obligate carnivory. Although the musculoskeletal anatomy of the Felidae has been studied extensively, the comparative neuroanatomy of felids is relatively unexplored. Little is known about how variation in the cerebral anatomy of felids relates to species-specific differences in sociality, hunting strategy, or activity patterns.

Resequencing of the TMF-1 (TATA Element Modulatory Factor) regulated protein (TRNP1) gene in domestic and wild canids.

Background: Cortical folding is related to the functional organization of the brain. The TMF-1 regulated protein (TRNP1) regulates the expansion and folding of the mammalian cerebral cortex, a process that may have been accelerated by the domestication of dogs. The objectives of this study were to sequence the TRNP1 gene in dogs and related canid species, provide evidence of its expression in dog brain and compare the genetic variation within dogs and across the Canidae.

Orexinergic neurons in the hypothalami of an Asiatic lion, an African lion, and a Southeast African cheetah.

Employing orexin-A immunohistochemistry, we describe the distribution, morphology, and nuclear parcellation of orexinergic neurons within the hypothalami of an Asiatic lion (Panthera leo subsp. persica), an African lion (Panthera leo subsp. melanochaita), and a Southeast African cheetah (Acinonyx jubatus subsp.

Sex estimation from dimensions of the base of the skull in Black South Africans.

The pelvis and the skull are the two most utilised skeletal elements to estimate sex from skeletonised remains due to their sexually dimorphic traits. However, as increasingly more fragmented remains have been presented for analyses, other bones and their fragments have now been subjected to analyses for sex estimation. In the skull particularly, the base has shown to survive harsh conditions.

The distribution, number, and certain neurochemical identities of infracortical white matter neurons in the brains of a southern lesser galago, a black-capped squirrel monkey, and a crested macaque.

In the current study, we examined the number, distribution, and aspects of the neurochemical identities of infracortical white matter neurons, also termed white matter interstitial cells (WMICs), in the brains of a southern lesser galago (Galago moholi), a black-capped squirrel monkey (Saimiri boliviensis boliviensis), and a crested macaque (Macaca nigra). Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most dense close to inner cortical border, decreasing in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed estimates of approximately 1.

Amplification of potential thermogenetic mechanisms in cetacean brains compared to artiodactyl brains.

To elucidate factors underlying the evolution of large brains in cetaceans, we examined 16 brains from 14 cetartiodactyl species, with immunohistochemical techniques, for evidence of non-shivering thermogenesis. We show that, in comparison to the 11 artiodactyl brains studied (from 11 species), the 5 cetacean brains (from 3 species), exhibit an expanded expression of uncoupling protein 1 (UCP1, UCPs being mitochondrial inner membrane proteins that dissipate the proton gradient to generate heat) in cortical neurons, immunolocalization of UCP4 within a substantial proportion of glia throughout the brain, and an increased density of noradrenergic axonal boutons (noradrenaline functioning to control concentrations of and activate UCPs). Thus, cetacean brains studied possess multiple characteristics indicative of intensified thermogenetic functionality that can be related to their current and historical obligatory aquatic niche.

Reproducibility of leftward planum temporale asymmetries in two genetically isolated populations of chimpanzees ().

Once considered a hallmark of human uniqueness, brain asymmetry has emerged as a feature shared with several other species, including chimpanzees, one of our closest living relatives. Most notable has been the discovery of asymmetries in homologues of cortical language areas in apes, particularly in the planum temporale (PT), considered a central node of the human language network. Several lines of evidence indicate a role for genetic mechanisms in the emergence of PT asymmetry; however, the genetic determinants of cerebral asymmetries have remained elusive.

The brain of the African wild dog. II. The olfactory system.

Employing a range of neuroanatomical stains, we detail the organization of the main and accessory olfactory systems of the African wild dog. The organization of both these systems follows that typically observed in mammals, but variations of interest were noted. Within the main olfactory bulb, the size of the glomeruli, at approximately 350 μm in diameter, are on the larger end of the range observed across mammals.

The brain of the African wild dog. IV. The visual system.

The variegated pelage and social complexity of the African wild dog (Lycaon pictus) hint at the possibility of specializations of the visual system. Here, using a range of architectural and immunohistochemical stains, we describe the systems-level organization of the image-forming, nonimage forming, oculomotor, and accessory optic, vision-associated systems in the brain of one representative individual of the African wild dog. For all of these systems, the organization, in terms of location, parcellation and topology (internal and external), is very similar to that reported in other carnivores.

Brain of the African wild dog. I. Anatomy, architecture, and volumetrics.

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 brain of the African wild dog. III. The auditory system.

The large external pinnae and extensive vocal repertoire of the African wild dog (Lycaon pictus) has led to the assumption that the auditory system of this unique canid may be specialized. Here, using cytoarchitecture, myeloarchitecture, and a range of immunohistochemical stains, we describe the systems-level anatomy of the auditory system of the African wild dog. We observed the cochlear nuclear complex, superior olivary nuclear complex, lateral lemniscus, inferior colliculus, medial geniculate body, and auditory cortex all being in their expected locations, and exhibiting the standard subdivisions of this system.

Brain gyrification in wild and domestic canids: Has domestication changed the gyrification index in domestic dogs?

Over the last 15 years, research on canid cognition has revealed that domestic dogs possess a surprising array of complex sociocognitive skills pointing to the possibility that the domestication process might have uniquely altered their brains; however, we know very little about how evolutionary processes (natural or artificial) might have modified underlying neural structure to support species-specific behaviors. Evaluating the degree of cortical folding (i.e.

Comparative neocortical neuromorphology in felids: African lion, African leopard, and cheetah.

The present study examines cortical neuronal morphology in the African lion (Panthera leo leo), African leopard (Panthera pardus pardus), and cheetah (Acinonyx jubatus jubatus). Tissue samples were removed from prefrontal, primary motor, and primary visual cortices and investigated with a Golgi stain and computer-assisted morphometry to provide somatodendritic measures of 652 neurons. Although neurons in the African lion were insufficiently impregnated for accurate quantitative dendritic measurements, descriptions of neuronal morphologies were still possible.

The brain of the tree pangolin (Manis tricuspis). VI. The brainstem and cerebellum.

The brainstem (midbrain, pons, and medulla oblongata) and cerebellum (diencephalic prosomere 1 through to rhombomere 11) play central roles in the processing of sensorimotor information, autonomic activity, levels of awareness and the control of functions external to the conscious cognitive world of mammals. As such, comparative analyses of these structures, especially the understanding of specializations or reductions of structures with functions that have been elucidated in commonly studied mammalian species, can provide crucial information for our understanding of the behavior of less commonly studied species, like pangolins. In the broadest sense, the nuclear complexes and subdivisions of nuclear complexes, the topographical arrangement, the neuronal chemistry, and fiber pathways of the tree pangolin conform to that typically observed across more commonly studied mammalian species.

Neuropil Distribution in the Anterior Cingulate and Occipital Cortex of Artiodactyls.

Relatively little neuroscience research has been focused on artiodactyls. Recent observations of complex social interactions in domestic and wild species suggest that analyses of artiodactyl brain anatomy would be of comparative value. In this study, we examined how the distribution of cortical neuropil space (a proxy for connectivity) varies across representative members of this diverse clade.

Scaling of the corpus callosum in wild and domestic canids: Insights into the domesticated brain.

All domesticated mammals exhibit marked reductions in overall brain size, however, it is unknown whether the corpus callosum (CC), an integral white matter fiber pathway for interhemispheric cortical communication, is affected by domestication differentially or strictly in coordination with changes in brain size. To answer this question, we used quantitative magnetic resonance imaging to compare the midsagittal cross-sectional areas of the CC in 35 carnivore species, including eight wild canids and 13 domestic dogs. We segmented rostro-caudal regions of interest for the CC and evaluated correlations with brain mass.

Hippocampal neurogenesis in the C57BL/6J mice at early adulthood following prenatal alcohol exposure.

We examined the effect of chronic prenatal alcohol exposure (PAE) on the process of adult neurogenesis in C57BL/6J mice at early adulthood (PND 56). Pregnant mice, and their in utero litters, were exposed to alcohol, through oral gavage, on gestational days 7-16, with recorded blood alcohol concentrations averaging 184 mg/dL (CA group). Two control groups, sucrose (CAc) and non-treated (NTc) control groups were also examined.

Organization of the sleep-related neural systems in the brain of the minke whale (Balaenoptera acutorostrata).

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.

Organization of the sleep-related neural systems in the brain of the river hippopotamus (Hippopotamus amphibius): A most unusual cetartiodactyl species.

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.

Organization of the sleep-related neural systems in the brain of the harbour porpoise (Phocoena phocoena).

The present study provides the first systematic immunohistochemical neuroanatomical investigation of the systems involved in the control and regulation of sleep in an odontocete cetacean, the harbor porpoise (Phocoena phocoena). The odontocete cetaceans show an unusual form of mammalian sleep, with unihemispheric slow waves, suppressed REM sleep, and continuous bodily movement. All the neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals were present in the harbor porpoise, with no specific nuclei being absent, and no novel nuclei being present.

Orexinergic bouton density is lower in the cerebral cortex of cetaceans compared to artiodactyls.

The species of the cetacean and artiodactyl suborders, which constitute the order Cetartiodactyla, exhibit very different sleep phenomenology, with artiodactyls showing typical bihemispheric slow wave and REM sleep, while cetaceans show unihemispheric slow wave sleep and appear to lack REM sleep. The aim of this study was to determine whether cetaceans and artiodactyls have differently organized orexinergic arousal systems by examining the density of orexinergic innervation to the cerebral cortex, as this projection will be involved in various aspects of cortical arousal. This study provides a comparison of orexinergic bouton density in the cerebral cortex of twelve Cetartiodactyla species (ten artiodactyls and two cetaceans) by means of immunohistochemical staining and stereological analysis.