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  • 1.

    【2hr】Development and Evolution of Cerebral and Cerebellar Cortex

    包量

    机译 脑和小脑皮质的发展和演变
    摘要：Cerebral cortex and cerebellar cortex both vary enormously across species in their size and complexity of convolutions. We discuss the development and evolution of cortical structures in terms of anatomy and functional organization. We propose that the distinctive shapes of cerebral and cerebellar cortex can be explained by relatively few developmental processes, notably including mechanical tension along axons and dendrites. Regarding functional organization, we show how maps of myelin content in cerebral cortex are evolutionarily conserved across primates but differ in the proportion of cortex devoted to sensory, cognitive, and other functions. We summarize recent progress and challenges in (i) parcellating cerebral cortex into a mosaic of distinct areas, (ii) distinguishing cortical areas that correspond across species from those that are present in one species but not another, and (iii) using this information along with surface-based interspecies registration to gain deeper insights into cortical evolution. We also comment on the methodological challenges imposed by the differences in anatomical and functional organization of cerebellar cortex relative to cerebral cortex.
  • 2.

    【2hr】Selective and context-dependent social and behavioral effects of Δ9-tetrahydrocannabinol in weakly electric fish.

    包量

    机译 弱电鱼中Δ9-四氢大麻酚的选择性和情境依赖性社会和行为影响。
    摘要：Cannabinoid (CB) receptors are widespread in the nervous system and influence a variety of behaviors. Weakly electric fish has been a useful model system in the study of the neural basis of behavior, but we know nothing of the role played by the CB system. Here, we determine the overall behavioral effect of a nonselective CB receptor agonist (i.e., Δ9-tetrahydrocannabinol, THC) in the weakly electric fish A. leptorhynchus. Using various behavioral paradigms involving social stimuli, we show that THC decreases locomotor behavior, as in many species, and influences the communication and social behavior. Across the different experiments, we found that the propensity to emit communication signals (chirps) and to seek social interactions was affected in a context-dependent manner. We explicitly tested this hypothesis by comparing the behavioral effects of THC injection in fish placed in a novel versus familiar social and physical environments. THC-injected fish were less likely to chirp than control in familiar situations but not in novel ones. The tendency to be in close proximity to other fish was affected only in novel environments with control fish clustering more than THC-injected ones. By identifying behaviors affected by CB agonists, our study can guide further comparative and neurophysiological studies of the role of the CB system using weakly electric fish as a model.
  • 3.

    【2hr】Brain activation patterns in response to conspecific and heterospecific social acoustic signals in female plainfin midshipman fish Porichthys notatus

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    机译 雌性中鳍鱼Porichthys notatus对同种和异种社会声学信号的响应的大脑激活模式
    摘要：While the peripheral auditory system of fishes has been well studied, less is known about how the fish’s brain and central auditory system process complex social acoustic signals. The plainfin midshipman fish, Porichthys notatus, has become a good species for investigating the neural basis of acoustic communication because the production and reception of acoustic signals is paramount for this species’ reproductive success. Nesting males produce long duration advertisement calls that females detect and localize amongst the noise in the intertidal zone to successfully find mates and spawn. How female midshipman are able to discriminate male advertisement calls from environmental noise and other acoustic stimuli is unknown. Using the immediate early gene product cFos as a marker for neural activity, we quantified neural activation of the ascending auditory pathway in female midshipman exposed to conspecific advertisement calls, heterospecific white seabass calls or ambient environment noise. We hypothesized that auditory hindbrain nuclei would be activated by general acoustic stimuli (ambient noise and other biotic acoustic stimuli) whereas auditory neurons in the midbrain and forebrain would be selectively activated by conspecific advertisement calls. We show that neural activation in two regions of the auditory hindbrain, the rostral intermediate division of the descending octaval nucleus and the ventral division of the secondary octaval nucleus, did not differ via cFos immunoreactive (cFos-ir) activity when exposed to different acoustic stimuli. In contrast, female midshipman exposed to conspecific advertisement calls showed greater cFos-ir in the nucleus centralis of the midbrain torus semicircularis compared to fish exposed only to ambient noise. No difference in cFos-ir was observed in the torus semicircularis of animals exposed to conspecific versus heterospecific calls. However, cFos-ir was greater in two forebrain structures that receive auditory input, the central posterior nucleus of the thalamus and the anterior tuberal hypothalamus, when exposed to conspecific calls versus exposure to either ambient noise or heterospecific calls. Our results suggest that higher order neurons in the female midshipman midbrain torus semicircularis, thalamic central posterior nucleus and hypothalamic anterior tuberal nucleus may be necessary for the discrimination of complex, specie-specific social acoustic signals. Furthermore, neurons in the central posterior and anterior tuberal nuclei are differentially activated by exposure to conspecific vs. other acoustic stimuli.
  • 4.

    【2hr】Midsagittal brain variation among non-human primates: insights into evolutionary expansion of the human precuneus

    包量

    机译 非人类灵长类动物的矢状中脑变异：人类前突神经进化的见解
    摘要：The precuneus is a major element of the superior parietal lobule, positioned on the medial side of the hemisphere and reaching the dorsal surface of the brain. It is a crucial functional region for visuospatial integration, visual imagery, and body coordination. Previously, we argued that the precuneus expanded in recent human evolution, based on a combination of paleontological, comparative, and intra-specific evidence from fossil and modern human endocasts as well as from human and chimpanzee brains. The longitudinal proportions of this region are a major source of anatomical variation among adult humans, and the main characteristic differentiating human midsagittal brain morphology from that of our closest living primate relative, the chimpanzee, being much larger in Homo sapiens. In the current shape analysis, we examine precuneus variation in non-human primates through landmark-based models, to evaluate the general pattern of variability in non-human primates, and to test whether precuneus proportions are influenced by allometric effects of brain size. Results show that precuneus proportions do not covary with brain size, and that the main difference between monkeys and apes involves a vertical expansion of the frontal and occipital regions in apes. Such differences might reflect differences in brain proportions or differences in cranial architecture. In this sample, precuneus variation is apparently not influenced by phylogenetic or allometric factors, but does vary consistently within species, at least in chimpanzees and macaques. This result further supports the hypothesis that precuneus expansion in modern humans is not merely a consequence of increasing brain size or of allometric scaling, but rather represents a species-specific morphological change in our lineage.
  • 5.

    【2hr】Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach

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    机译 类人猿灵长类动物小脑和新皮质扩展的遗传学：一种比较方法
    摘要：What adaptive changes in brain structure and function underpin the evolution of increased cognitive performance in humans and our close relatives? Identifying the genetic basis of brain evolution has become a major tool in answering this question. Numerous cases of positive selection, altered gene expression or gene duplication have been identified that may contribute to the evolution of the neocortex, which is widely assumed to play a predominant role in cognitive evolution. However, the components of the neocortex co-evolve with other functionally interdependent regions of the brain, most notably in the cerebellum. The cerebellum is linked to a range of cognitive tasks and expanded rapidly during hominoid evolution. Here we present data that suggest that, across anthropoid primates, protein-coding genes with known roles in cerebellum development were just as likely to be targeted by selection as genes linked to cortical development. Indeed, based on currently available gene ontology data, protein-coding genes with known roles in cerebellum development are more likely to have evolved adaptively during hominoid evolution. This is consistent with phenotypic data suggesting an accelerated rate of cerebellar expansion in apes that is beyond that predicted from scaling with the neocortex in other primates. Finally, we present evidence that the strength of selection on specific genes is associated with variation in the volume of either the neocortex or the cerebellum, but not both. This result provides preliminary evidence that co-variation between these brain components during anthropoid evolution may be at least partly regulated by selection on independent loci, a conclusion that is consistent with recent intraspecific genetic analyses and a mosaic model of brain evolution that predicts adaptive evolution of brain structure.
  • 6.

    【2hr】Electrical Potential of Leaping Eels

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    机译 E鱼的电势
    摘要：When approached by a large, partially submerged conductor, electric eels (Electrophorus electricus) will often defend themselves by leaping from the water to directly shock the threat. Presumably, the conductor is interpreted as an approaching terrestrial or semiaquatic animal. In the course of this defensive behavior, eels first make direct contact with their lower jaw and then rapidly emerge from the water, ascending the conductor while discharging high-voltage volleys. In this study, the equivalent circuit that develops during this behavior was proposed and investigated. First, the electromotive force and internal resistance of four electric eels were determined. These values were then used to estimate the resistance of the water volume between the eel and the conductor by making direct measurements of current with the eel and water in the circuit. The resistance of the return path from the eel's lower jaw to the main body of water was then determined, based on voltage recordings, for each electric eel at the height of the defensive leap. Finally, the addition of a hypothetical target for the leaping defense was considered as part of the circuit. The results suggest the defensive behavior efficiently directs electrical current through the threat, producing an aversive and deterring experience by activating afferents in potential predators.
  • 7.

    【2hr】Comparison of Dolphins Body and Brain Measurements with Four Other Groups of Cetaceans Reveals Great Diversity

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    机译 海豚的身体和大脑测量值与其他四类鲸类动物的比较显示出极大的多样性
    摘要：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.
  • 8.

    【2hr】Song in an affiliative context relates to the neural expression of dopamine- and neurotensin-related genes in male European starlings

    包量

    机译 亲属关系中的歌曲与欧洲八哥犬中多巴胺和神经降压素相关基因的神经表达有关
    摘要：Some animals, including songbirds, vocalize at high rates when alone or in large groups. In songbirds, vocal behavior in these contexts is important for song learning and group cohesion. It is not obviously targeted at any particular individual and is described as “undirected.” Studies suggest a role for dopamine in undirected song. The neuropeptide neurotensin can enhance dopaminergic signaling upon binding to the neurotensin receptor 1 (NTR1) and is found in regions where dopamine can influence song, including the ventral tegmental area (VTA), septum, and the song-control nucleus Area X. To begin to test the hypothesis that neurotensin and dopamine in these regions interact to influence undirected song, we used quantitative real time PCR to relate undirected singing to mRNA expression of neurotensin, NTR1, tyrosine hydroxylase (a synthetic enzyme for dopamine), and D1 and D2 receptors in male European starlings. Tyrosine hydroxylase and neurotensin expression in VTA, and neurotensin and D1 expression in Area X, positively correlated with song. Neurotensin markers also correlated positively with dopamine markers in VTA. Given the role of VTA projections to Area X in song learning, these results suggest that interactions between neurotensin and dopamine in these regions may contribute to vocal learning. In septum, NTR1 expression positively correlated with song, and neurotensin and dopamine markers were correlated, suggesting that neurotensin in this region may influence dopaminergic transmission to facilitate undirected vocalizations. Overall, these findings implicate interactions between neurotensin and dopamine in affiliative communication.
  • 9.

    【2hr】Sound localization strategies in three predators

    包量

    机译 三种掠食者的合理定位策略
    摘要：In this review we will discuss some of the neural strategies for sound localization and encoding interaural time differences (ITDs) in three predatory species of Reptilia, alligators, barn owls and geckos. Birds and crocodilians are sister groups among the extant archosaurs, while geckos are lepidosaurs. Despite the similar organization of their auditory systems, archosaurs and lizards use different strategies for encoding the ITDs that underlie localization of sound in azimuth. Barn owls encode ITD information using a place map, composed of neurons serving as labeled lines tuned for preferred spatial locations, while geckos may use a meter strategy, or population code composed of broadly sensitive neurons that represent ITD via changes in firing rate.
  • 10.

    【2hr】Elaboration and Innervation of the Vibrissal System in the Rock Hyrax (Procavia capensis)

    包量

    机译 非洲蹄兔（Procavia capensis）的振动系统的细化和神经支配
    摘要：Mammalian tactile hairs are commonly found on specific, restricted regions of the body, but Florida manatees represent a unique exception, exhibiting follicle-sinus complexes (FSCs, also known as vibrissae or tactile hairs) on their entire body. The orders Sirenia (including manatees and dugongs) and Hyracoidea (hyraxes) are thought to have diverged approximately 60 mya, yet hyraxes are among the closest relatives to sirenians. We investigated the possibility that hyraxes, like manatees, are tactile specialists with vibrissae that cover the entire post-facial body. Previous studies suggested that rock hyraxes possess post-facial vibrissae in addition to pelage hair, but this observation was not verified through histological examination. Using a detailed immunohistochemical analysis, we characterized the gross morphology, innervation, and mechanoreceptors present in FSCs sampled from facial and post-facial vibrissae body regions to determine that the long post-facial hairs on the hyrax body are in fact true vibrissae. The types and relative densities of mechanoreceptors associated with each FSC also appeared to be relatively consistent between facial and post-facial FSCs. The presence of vibrissae covering the hyrax body presumably facilitates navigation in the dark caves and rocky crevices of the hyrax's environment where visual cues are limited, and may alert the animal to predatory or conspecific threats approaching the body. Furthermore, the presence of vibrissae on the post-facial body in both manatees and hyraxes indicates that this distribution may represent the ancestral condition for the supraorder Paenungulata.
  • 11.

    【2hr】Decoding the molecular evolution of human cognition using comparative genomics

    包量

    机译 使用比较基因组学解码人类认知的分子进化
    摘要：Identification of genetic and molecular factors responsible for the specialized cognitive abilities of humans is expected to provide important insights into the mechanisms responsible for disorders of cognition such as autism, schizophrenia, and Alzheimer’s disease. Here, we discuss the use of comparative genomics for identifying salient genes and gene networks that may underlie cognition. We focus on the comparison of human and non-human primate brain gene expression and the utility of building gene co-expression networks for prioritizing hundreds of genes that differ in expression among the species queried. We also discuss the importance and methods for functional studies of individual genes identified. Together, this integration of comparative genomics with cellular and animal models should provide improved systems for developing effective therapeutics for disorders of cognition.
  • 12.

    【2hr】Evolution of the Central Sulcus Morphology in Primates

    包量

    机译 灵长类动物中央沟形态的演变
    摘要：The central sulcus (CS) divides the pre- and post-central gyri along the dorsal-ventral plane of which all motor and sensory functions are topographically organized. The motor-hand area of the precentral gyrus or knob has been described as the anatomical substrate of the hand in humans. Given the importance of the hand in primate evolution, here we examined the evolution of the motor-hand area by comparing the relative size and pattern of cortical folding of the CS surface area from magnetic resonance images in 131 primates including Old World monkeys, apes, and humans. We found that humans and great apes have a well-formed motor-hand area that can be seen in the variation in depth of the CS along the dorsal-ventral plane. We further found that great apes have relatively large CS surface areas compared to Old World monkeys. However, relative to great apes, humans have a small motor-hand area in terms of both adjusted and absolute surface areas.
  • 13.

    【2hr】Evolution and development of the mammalian cerebral cortex

    包量

    机译 哺乳动物大脑皮层的进化与发展
    摘要：Comparative developmental studies of the mammalian brain can identify key changes that can generate the diverse structures and functions of brains. We have studied how the neocortex of early mammals became organized into functionally distinct areas, and how the current level of cortical cellular and laminar specialization arose from the simpler premammalian cortex. We demonstrate the neocortical organization in early mammals that is most informative for an understanding of how the large, complex human brain evolved from a long line of ancestors. The radial and tangential enlargement of the cortex was driven by changes in the patterns of cortical neurogenesis, including alterations in the proportions of distinct progenitor types. Some cortical cell populations travel to the cortex through tangential migration, others migrate radially. A number of recent studies have begun to characterize the chick, mouse, human and non-human primate cortical transcriptome to help us understand how gene expression relates to the development, and to the anatomical and functional organization of the adult neocortex. Although all mammalian forms share the basic layout of cortical areas, the areal proportions and distributions are driven by distinct evolutionary pressures acting on sensory and motor experiences during the individual ontogenies.
  • 14.

    【2hr】NSF Workshop Report: Discovering General Principles of Nervous System Organization by Comparing Brain Maps across Species

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    机译 NSF研讨会报告：通过比较各种物种的大脑图来发现神经系统组织的一般原则
    摘要：Efforts to understand nervous system structure and function have received new impetus from the federal Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Comparative analyses can contribute to this effort by leading to the discovery of general principles of neural circuit design, information processing, and gene-structure-function relationships that are not apparent from studies on single species. We here propose to extend the comparative approach to nervous system ‘maps’ comprising molecular, anatomical, and physiological data. This research will identify which neural features are likely to generalize across species, and which are unlikely to be broadly conserved. It will also suggest causal relationships between genes, development, adult anatomy, physiology, and, ultimately, behavior. These causal hypotheses can then be tested experimentally. Finally, insights from comparative research can inspire and guide technological development. To promote this research agenda, we recommend that teams of investigators coalesce around specific research questions and select a set of ‘reference species’ to anchor their comparative analyses. These reference species should be chosen not just for practical advantages, but also with regard for their phylogenetic position, behavioral repertoire, well-annotated genome, or other strategic reasons. We envision that the nervous systems of these reference species will be mapped in more detail than those of other species. The collected data may range from the molecular to the behavioral, depending on the research question. To integrate across levels of analysis and across species, standards for data collection, annotation, archiving, and distribution must be developed and respected. To that end, it will help to form networks or consortia of researchers and centers for science, technology, and education that focus on organized data collection, distribution, and training. These activities could be supported, at least in part, through existing mechanisms at NSF, NIH, and other agencies. It will also be important to develop new integrated software and database systems for cross-species data analyses. Multidisciplinary efforts to develop such analytical tools should be supported financially. Finally, training opportunities should be created to stimulate multidisciplinary, integrative research into brain structure, function, and evolution.
  • 15.

    【2hr】Things Change – How Comparative Transcriptomics Suggests the Pallium has Evolved at Multiple Levels of Organization

    包量

    机译 事物发生了变化–比较转录组学如何暗示大脑皮层已在多个组织层面发展
    摘要：
  • 16.

    【2hr】Rhesus macaques recognize unique multi-modal face-voice relations of familiar individuals and not of unfamiliar ones

    包量

    机译 恒河猴认识到熟悉的人而不是陌生的人的独特的多模式面部声音关系
    摘要：Communication signals in non-human primates are inherently multi-modal. However, for laboratory-housed monkeys, there is relatively little evidence in support of the use of multi-modal communication signals in individual recognition. Here, we used a preferential-looking paradigm to test whether laboratory-housed rhesus could “spontaneously” (i.e., in the absence of operant training) use multi-modal communication stimuli to discriminate between known conspecifics. The multi-modal stimulus was a silent movie of two monkeys vocalizing and an audio file of the vocalization from one of the monkeys in the movie. We found that the gaze patterns of those monkeys that knew the individuals in the movie were reliably biased toward the individual that did not produce the vocalization. In contrast, there was not a systematic gaze pattern for those monkeys that did not know the individuals in the movie. These data are consistent with the hypothesis that laboratory-housed rhesus can recognize and distinguish between conspecifics based on auditory and visual communication signals.
  • 17.

    【2hr】Variation in human brains may facilitate evolutionary change toward a limited range of phenotypes

    包量

    机译 人脑的变异可能有助于向有限表型的进化变化
    摘要：Individual variation is the foundation for evolutionary change, but little is known about the nature of normal variation between brains. Phylogenetic variation across mammalian brains is characterized by high inter-correlations in brain region volumes, distinct allometric scaling for each brain region and the relative independence in olfactory and limbic structures volumes from the rest of the brain. Previous work examining brain variation in individuals of some domesticated species showed that these three features of phylogenetic variation were mirrored in individual variation. We extend this analysis to the human brain and 10 of its subdivisions (e.g., isocortex, hippocampus) by using magnetic resonance imaging scans of 90 human brains ranging between 16 to 25 years of age. Human brain variation resembles both the individual variation seen in other species, and variation observed across mammalian species. That is, the relative differences in the slopes of each brain region compared to medulla size within humans and between mammals are concordant, and limbic structures scale with relative independence from other brain regions. This non-random pattern of variation suggests that developmental programs channel the variation available for selection.
  • 18.

    【2hr】Evidence for Ape and Human Specializations in Geniculostriate Projections from VGLUT2 Immunohistochemistry

    包量

    机译 VGLUT2免疫组化在细齿ate虫投射中的猿类和人类专长的证据
    摘要：Vesicular glutamate transporters reuptake glutamate into synaptic vesicles at excitatory synapses. Vesicular glutamate transporter 2 (VGLUT2) is localized in the cortical terminals of neuronal somas located in the main sensory nuclei of the thalamus. Thus, immunolabeling of cortex with antibodies to VGLUT2 can reveal geniculostriate terminal distributions in species in which connectivity cannot be studied with tract-tracing techniques, permitting broader comparative studies of cortical specializations. Here, we used VGLUT2 immunohistochemistry to compare the organization of geniculostriate afferents in primary visual cortex in hominid primates (humans, chimpanzees, orangutan), Old World monkeys (rhesus macaques, vervets), and New World monkeys (squirrel monkeys). The New World and Old World monkeys had a broad, dense band of terminal-like labeling in cortical layer 4C, a narrow band of labeling in layer 4A, and additional labeling in layers 2/3 and 6, consistent with results from conventional tract-tracing studies in these species. By contrast, although the hominid primates had a prominent layer 4C band, labeling of layer 4A was sparse or absent. Label was also present in layers 2/3 and 6, although labeling of layer 6 in hominids was weaker and possibly more individually variable than in Old World and New World monkeys. These findings are consistent with previous observations from cytochrome oxidase histochemistry and a very small number of connectivity studies, suggesting that the projection from the parvocellular layers of the lateral geniculate nucleus to layer 4A were strongly reduced or eliminated in humans and apes following their evolutionary divergence from the other anthropoid primates.
  • 19.

    【2hr】Socially Modulated Cell Proliferation Is Independent of Gonadal Steroid Hormones in the Brain of the Adult Green Treefrog (Hyla cinerea)

    包量

    机译 社会调节的细胞增殖与成年绿树蛙（Hyla cinerea）脑中的性腺类固醇激素无关。
    摘要：Gonadal steroid hormones have been shown to influence adult neurogenesis in addition to their well-defined role in regulating social behavior. Adult neurogenesis consists of several processes including cell proliferation, which can be studied via 5-bromo-2′-deoxyuridine (BrdU) labeling. In a previous study we found that social stimulation altered both cell proliferation and levels of circulating gonadal steroids, leaving the issue of cause/effect unclear. In this study, we sought to determine whether socially modulated BrdU-labeling depends on gonadal hormone changes. We investigated this using a gonadectomy-implant paradigm and by exposing male and female green treefrogs (Hyla cinerea) to their conspecific chorus or control stimuli (i.e. random tones). Our results indicate that socially modulated cell proliferation occurred independently of gonadal hormone levels; furthermore, neither androgens in males nor estrogen in females increased cell proliferation in the preoptic area (POA) and infundibular hypothalamus, brain regions involved in endocrine regulation and acoustic communication. In fact, elevated estrogen levels decreased cell proliferation in those brain regions in the implanted female. In male frogs, evoked calling behavior was positively correlated with BrdU-labeling in the POA; however, statistical analysis showed that this behavior did not mediate socially induced cell proliferation. These results show that the social modulation of cell proliferation can occur without gonadal hormone involvement in either male or female adult anuran amphibians, and confirms that it is independent of a behavioral response in males.
  • 20.

    【2hr】Updated Neuronal Scaling Rules for the Brains of Glires (Rodents/Lagomorphs)

    包量

    机译 更新了针对神经元大脑的神经元缩放规则（啮齿动物/ Lagomorphs）
    摘要：Brain size scales as different functions of its number of neurons across mammalian orders such as rodents, primates, and insectivores. In rodents, we have previously shown that, across a sample of 6 species, from mouse to capybara, the cerebral cortex, cerebellum and the remaining brain structures increase in size faster than they gain neurons, with an accompanying decrease in neuronal density in these structures [Herculano-Houzel et al.: Proc Natl Acad Sci USA 2006;103:12138–12143]. Important remaining questions are whether such neuronal scaling rules within an order apply equally to all pertaining species, and whether they extend to closely related taxa. Here, we examine whether 4 other species of Rodentia, as well as the closely related rabbit (Lagomorpha), conform to the scaling rules identified previously for rodents. We report the updated neuronal scaling rules obtained for the average values of each species in a way that is directly comparable to the scaling rules that apply to primates [Gabi et al.: Brain Behav Evol 2010;76:32–44], and examine whether the scaling relationships are affected when phylogenetic relatedness in the dataset is accounted for. We have found that the brains of the spiny rat, squirrel, prairie dog and rabbit conform to the neuronal scaling rules that apply to the previous sample of rodents. The conformity to the previous rules of the new set of species, which includes the rabbit, suggests that the cellular scaling rules we have identified apply to rodents in general, and probably to Glires as a whole (rodents/lagomorphs), with one notable exception: the naked mole-rat brain is apparently an outlier, with only about half of the neurons expected from its brain size in its cerebral cortex and cerebellum.
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