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Mulholland MM, Meguerditchian A, Hopkins WD. Age- and sex-related differences in baboon (Papio anubis) gray matter covariation. Neurobiol Aging 2023; 125:41-48. [PMID: 36827943 PMCID: PMC10308318 DOI: 10.1016/j.neurobiolaging.2023.01.005] [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: 10/29/2021] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/30/2023]
Abstract
Age-related changes in cognition, brain morphology, and behavior are exhibited in several primate species. Baboons, like humans, naturally develop Alzheimer's disease-like pathology and cognitive declines with age and are an underutilized model for studies of aging. To determine age-related differences in gray matter covariation of 89 olive baboons (Papio anubis), we used source-based morphometry (SBM) to analyze data from magnetic resonance images. We hypothesized that we would find significant age effects in one or more SBM components, particularly those which include regions influenced by age in humans and other nonhuman primates (NHPs). A multivariate analysis of variance revealed that individual weighted gray matter covariation scores differed across the age classes. Elderly baboons contributed significantly less to gray matter covariation components including the brainstem, superior parietal cortex, thalamus, and pallidum compared to juveniles, and middle and superior frontal cortex compared to juveniles and young adults (p < 0.05). Future studies should examine the relationship between the changes in gray matter covariation reported here and age-related cognitive decline.
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Affiliation(s)
- M M Mulholland
- The University of Texas MD Anderson Cancer Center, Bastrop, TX.
| | - A Meguerditchian
- Laboratoire de Psychologie Cognitive UMR7290, LPC, CNRS, Aix-Marseille University, Institute of Language, Communication and the Brain, Marseille, France; Station de Primatologie-Celphedia, UAR846, Rousset, France
| | - W D Hopkins
- The University of Texas MD Anderson Cancer Center, Bastrop, TX
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2
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Bruner E, Battaglia-Mayer A, Caminiti R. The parietal lobe evolution and the emergence of material culture in the human genus. Brain Struct Funct 2023; 228:145-167. [PMID: 35451642 DOI: 10.1007/s00429-022-02487-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/24/2022] [Indexed: 02/07/2023]
Abstract
Traditional and new disciplines converge in suggesting that the parietal lobe underwent a considerable expansion during human evolution. Through the study of endocasts and shape analysis, paleoneurology has shown an increased globularity of the braincase and bulging of the parietal region in modern humans, as compared to other human species, including Neandertals. Cortical complexity increased in both the superior and inferior parietal lobules. Emerging fields bridging archaeology and neuroscience supply further evidence of the involvement of the parietal cortex in human-specific behaviors related to visuospatial capacity, technological integration, self-awareness, numerosity, mathematical reasoning and language. Here, we complement these inferences on the parietal lobe evolution, with results from more classical neuroscience disciplines, such as behavioral neurophysiology, functional neuroimaging, and brain lesions; and apply these to define the neural substrates and the role of the parietal lobes in the emergence of functions at the core of material culture, such as tool-making, tool use and constructional abilities.
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Affiliation(s)
- Emiliano Bruner
- Centro Nacional de Investigación Sobre la Evolución Humana, Burgos, Spain
| | | | - Roberto Caminiti
- Neuroscience and Behavior Laboratory, Istituto Italiano di Tecnologia (IIT), Roma, Italy.
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3
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Hopkins WD, Mulholland MM, Mareno MC, Webb SJN, Schapiro SJ. Neuroanatomical correlates of individual differences in the object choice task in chimpanzees ( Pan troglodytes). Front Psychol 2022; 13:1057722. [PMID: 36507015 PMCID: PMC9732552 DOI: 10.3389/fpsyg.2022.1057722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 10/25/2022] [Indexed: 11/26/2022] Open
Abstract
Declarative and imperative joint attention or joint engagement are important milestones in human infant development. These have been shown to be a significant predictor of later language development and are impaired in some individuals with, or at risk for, a diagnosis of autism spectrum disorder. Comparatively, while chimpanzees and other great apes have been reported to engage in imperative joint attention, evidence of declarative joint attention remains unclear based on existing studies. Some have suggested that differences in methods of assessing joint attention may have an influence on performance in nonhuman primates. Here, we report data on a measure of receptive joint attention (object choice task) in a sample of captive chimpanzees. Chimpanzees, as a group, performed significantly better than chance. By contrast, when considering individual performance, there was no significant difference in the number of those who passed and those who failed. Using quantitative genetic analyses, we found that performance on the object choice task was not significantly heritable nor were there any significant effects of sex, rearing history, or colony. Lastly, we found significant differences in gray matter covariation, between those who passed or failed the task. Those who passed contributed more to gray matter covariation in several brain regions within the social brain network, consistent with hypotheses regarding the importance of these regions in human and nonhuman primate social cognition.
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Affiliation(s)
- William D. Hopkins
- Department of Comparative Medicine, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
| | - Michele M. Mulholland
- Department of Comparative Medicine, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
| | - Mary Catherine Mareno
- Department of Comparative Medicine, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
| | - Sarah J. Neal Webb
- Department of Comparative Medicine, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
| | - Steven J. Schapiro
- Department of Comparative Medicine, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
- Department of Experimental Medicine, University of Copenhagen, Copenhagen, Denmark
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4
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Mulholland MM, Schapiro SJ, Sherwood CC, Hopkins WD. Phenotypic and genetic associations between gray matter covariation and tool use skill in chimpanzees (Pan troglodytes): Repeatability in two genetically isolated populations. Neuroimage 2022; 257:119292. [PMID: 35551989 PMCID: PMC9351395 DOI: 10.1016/j.neuroimage.2022.119292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/13/2022] [Accepted: 05/08/2022] [Indexed: 11/19/2022] Open
Abstract
Humans and chimpanzees both exhibit a diverse set of tool use skills which suggests selection for tool manufacture and use occurred in the common ancestors of the two species. Our group has previously reported phenotypic and genetic associations between tool use skill and gray matter covariation, as quantified by source-based morphometry (SBM), in chimpanzees. As a follow up study, here we evaluated repeatability in heritability in SBM components and their phenotypic association with tool use skill in two genetically independent chimpanzee cohorts. Within the two independent cohorts of chimpanzees, we identified 8 and 16 SBM components, respectively. Significant heritability was evident for multiple SBM components within both cohorts. Further, phenotypic associations between tool use performance and the SBM components were largely consistent between the two cohorts; the most consistent finding being an association between tool use performance and an SBM component including the posterior superior temporal sulcus (STS) and superior temporal gyrus (STG), and the interior and superior parietal regions (p< 0.05). These findings indicate that the STS, STG, and parietal cortices are phenotypically and genetically implicated in chimpanzee tool use abilities.
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Affiliation(s)
- M M Mulholland
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, 650 Cool Water Drive, Bastrop, TX 78602, USA.
| | - S J Schapiro
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, 650 Cool Water Drive, Bastrop, TX 78602, USA; Department of Experimental Medicine, University of Copenhagen, Copenhagen, Denmark
| | - C C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | - W D Hopkins
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, 650 Cool Water Drive, Bastrop, TX 78602, USA
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5
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Gray Matter Variation in the Posterior Superior Temporal Gyrus Is Associated with Polymorphisms in the KIAA0319 Gene in Chimpanzees ( Pan troglodytes). eNeuro 2021; 8:ENEURO.0169-21.2021. [PMID: 34815295 PMCID: PMC8672446 DOI: 10.1523/eneuro.0169-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Determining the impact that the KIAA0319 gene has on primate brain morphology can provide insight into the evolution of human cognition and language systems. Here, we tested whether polymorphisms in KIAA0319 in chimpanzees account for gray matter volumetric variation in brain regions implicated in language and communication (particularly within the posterior superior temporal gyrus and inferior frontal gyrus). First, we identified the nature and frequencies of single nucleotide variants (SNVs) in KIAA0319 in a sample of unrelated chimpanzees (Pan troglodytes spp.). Next, we genotyped a subset of SNVs (those important for gene regulation or likely to alter protein structure/function) in a sample of chimpanzees for which in vivo T1-structural magnetic resonance imaging scans had been obtained. We then used source-based morphometry (SBM) to test for whole-brain gray matter covariation differences between chimpanzees with different KIAA0319 alleles. Finally, using histologic sections of 15 postmortem chimpanzee brains, we analyzed microstructural variation related to KIAA0319 polymorphisms in the posterior superior temporal cortex. We found that the SNVs were associated with variation in gray matter within several brain regions, including the posterior superior temporal gyrus (a region associated with language comprehension and production in humans). The microstructure analysis further revealed hemispheric differences in neuropil fraction, indicating that KIAA0319 expression may be involved in regulation of processes related to the formation and maintenance of synapses, dendrites, or axons within regions associated with communication.
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Hecht EE, Kukekova AV, Gutman DA, Acland GM, Preuss TM, Trut LN. Neuromorphological Changes following Selection for Tameness and Aggression in the Russian Farm-Fox experiment. J Neurosci 2021; 41:6144-6156. [PMID: 34127519 PMCID: PMC8276742 DOI: 10.1523/jneurosci.3114-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 01/13/2023] Open
Abstract
The Russian farm-fox experiment is an unusually long-running and well-controlled study designed to replicate wolf-to-dog domestication. As such, it offers an unprecedented window onto the neural mechanisms governing the evolution of behavior. Here we report evolved changes to gray matter morphology resulting from selection for tameness versus aggressive responses toward humans in a sample of 30 male fox brains. Contrasting with standing ideas on the effects of domestication on brain size, tame foxes did not show reduced brain volume. Rather, gray matter volume in both the tame and aggressive strains was increased relative to conventional farm foxes bred without deliberate selection on behavior. Furthermore, tame- and aggressive-enlarged regions overlapped substantially, including portions of motor, somatosensory, and prefrontal cortex, amygdala, hippocampus, and cerebellum. We also observed differential morphologic covariation across distributed gray matter networks. In one prefrontal-cerebellum network, this covariation differentiated the three populations along the tame-aggressive behavioral axis. Surprisingly, a prefrontal-hypothalamic network differentiated the tame and aggressive foxes together from the conventional strain. These findings indicate that selection for opposite behaviors can influence brain morphology in a similar way.SIGNIFICANCE STATEMENT Domestication represents one of the largest and most rapid evolutionary shifts of life on earth. However, its neural correlates are largely unknown. Here we report the neuroanatomical consequences of selective breeding for tameness or aggression in the seminal Russian farm-fox experiment. Compared with a population of conventional farm-bred control foxes, tame foxes show neuroanatomical changes in the PFC and hypothalamus, paralleling wolf-to-dog shifts. Surprisingly, though, aggressive foxes also show similar changes. Moreover, both strains show increased gray matter volume relative to controls. These results indicate that similar brain adaptations can result from selection for opposite behavior, that existing ideas of brain changes in domestication may need revision, and that significant neuroanatomical change can evolve very quickly, within the span of <100 generations.
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Affiliation(s)
- Erin E Hecht
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Anna V Kukekova
- Department of Animal Sciences, College of Agriculture, Consumer, and Environmental Sciences, University of IL Urbana-Champaign, Urbana, IL 61801
| | | | - Gregory M Acland
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, 14853
| | - Todd M Preuss
- Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322
| | - Lyudmila N Trut
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia, 630090
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7
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Qing Z, Chen F, Lu J, Lv P, Li W, Liang X, Wang M, Wang Z, Zhang X, Zhang B. Causal structural covariance network revealing atrophy progression in Alzheimer's disease continuum. Hum Brain Mapp 2021; 42:3950-3962. [PMID: 33978292 PMCID: PMC8288084 DOI: 10.1002/hbm.25531] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 04/10/2021] [Accepted: 04/26/2021] [Indexed: 01/24/2023] Open
Abstract
The structural covariance network (SCN) has provided a perspective on the large‐scale brain organization impairment in the Alzheimer's Disease (AD) continuum. However, the successive structural impairment across brain regions, which may underlie the disrupted SCN in the AD continuum, is not well understood. In the current study, we enrolled 446 subjects with AD, mild cognitive impairment (MCI) or normal aging (NA) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The SCN as well as a casual SCN (CaSCN) based on Granger causality analysis were applied to the T1‐weighted structural magnetic resonance images of the subjects. Compared with that of the NAs, the SCN was disrupted in the MCI and AD subjects, with the hippocampus and left middle temporal lobe being the most impaired nodes, which is in line with previous studies. In contrast, according to the 194 subjects with records on CSF amyloid and Tau, the CaSCN revealed that during AD progression, the CaSCN was enhanced. Specifically, the hippocampus, thalamus, and precuneus/posterior cingulate cortex (PCC) were identified as the core regions in which atrophy originated and could predict atrophy in other brain regions. Taken together, these findings provide a comprehensive view of brain atrophy in the AD continuum and the relationships among the brain atrophy in different regions, which may provide novel insight into the progression of AD.
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Affiliation(s)
- Zhao Qing
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Institute of Brain Science, Nanjing University, Nanjing, China
| | - Feng Chen
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jiaming Lu
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Pin Lv
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Weiping Li
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xue Liang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Maoxue Wang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Zhengge Wang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xin Zhang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Bing Zhang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Institute of Brain Science, Nanjing University, Nanjing, China
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8
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Westerhausen R, Fjell AM, Kompus K, Schapiro SJ, Sherwood CC, Walhovd KB, Hopkins WD. Comparative morphology of the corpus callosum across the adult lifespan in chimpanzees (Pan troglodytes) and humans. J Comp Neurol 2021; 529:1584-1596. [PMID: 32978976 PMCID: PMC7987726 DOI: 10.1002/cne.25039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 12/14/2022]
Abstract
The human corpus callosum exhibits substantial atrophy in old age, which is stronger than what would be predicted from parallel changes in overall brain anatomy. To date, however, it has not been conclusively established whether this accentuated decline represents a common feature of brain aging across species, or whether it is a specific characteristic of the aging human brain. In the present cross-sectional study, we address this question by comparing age-related difference in corpus callosum morphology of chimpanzees and humans. For this purpose, we measured total midsagittal area and regional thickness of the corpus callosum from T1-weighted MRI data from 213 chimpanzees, aged between 9 and 54 years. The results were compared with data drawn from a large-scale human sample which was age-range matched using two strategies: (a) matching by chronological age (human sample size: n = 562), or (b) matching by accounting for differences in longevity and various maturational events between the species (i.e., adjusted human age range: 13.6 to 80.9 years; n = 664). Using generalized additive modeling to fit and compare aging trajectories, we found significant differences between the two species. The chimpanzee aging trajectory compared with the human trajectory was characterized by a slower increase from adolescence to middle adulthood, and by a lack of substantial decline from middle to old adulthood, which, however, was present in humans. Thus, the accentuated decline of the corpus callosum found in aging humans is not a universal characteristic of the aging brain, and appears to be human-specific.
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Affiliation(s)
- René Westerhausen
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Norway
| | - Anders M. Fjell
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Norway
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway
| | - Kristiina Kompus
- Department of Biological and Medical Psychology, University of Bergen, Norway
- Institute of Psychology, University of Tartu, Estonia
| | - Steven J. Schapiro
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, UT MD Anderson Cancer Center, Bastrop, Texas, USA
- Department of Experimental Medicine, University of Copenhagen, Denmark
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, USA
| | - Kristine B. Walhovd
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Norway
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway
| | - William D. Hopkins
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, UT MD Anderson Cancer Center, Bastrop, Texas, USA
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9
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Mulholland MM, Sherwood CC, Schapiro SJ, Raghanti MA, Hopkins WD. Age- and cognition-related differences in the gray matter volume of the chimpanzee brain (Pan troglodytes): A voxel-based morphometry and conjunction analysis. Am J Primatol 2021; 83:e23264. [PMID: 33899958 DOI: 10.1002/ajp.23264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/29/2021] [Accepted: 04/10/2021] [Indexed: 01/01/2023]
Abstract
Several primate species have been shown to exhibit age-related changes in cognition, brain, and behavior. However, severe neurodegenerative illnesses, such as Alzheimer's disease (AD), were once thought to be uniquely human. Recently, some chimpanzees naturally were documented to develop both neurofibrillary tangles and amyloid plaques, the main characteristics of AD pathology. In addition, like humans and other primates, chimpanzees show similar declines in cognition and motor function with age. Here, we used voxel-based morphometry to examine the relationships among gray matter volume, age, and cognition using magnetic resonance imaging scans previously acquired from chimpanzees (N = 216). We first determined the relationship between age and gray matter volume, identifying the regions that declined with age. With a subset of our sample (N = 103), we also determined differences in gray matter volume between older chimpanzees with higher cognition scores than expected for their age, and older chimpanzees with lower than expected scores. Finally, we ran a conjunction analysis to determine any overlap in brain regions between these two analyses. We found that as chimpanzees age, they lose gray matter in regions associated with cognition. In addition, cognitively healthy older chimpanzees (those performing better for their age) have greater gray matter volume in many brain regions compared with chimpanzees who underperform for their age. Finally, the conjunction analysis revealed that regions of age-related decline overlap with the regions that differ between cognitively healthy chimpanzees and those who underperform. This study provides further evidence that chimpanzees are an important model for research on the neurobiology of aging. Future studies should investigate the effects of cognitive stimulation on both cognitive performance and brain structure in aging nonhuman primates.
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Affiliation(s)
- Michele M Mulholland
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, Texas, USA
| | - Chet C Sherwood
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington DC, USA
| | - Steven J Schapiro
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, Texas, USA.,Department of Experimental Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - William D Hopkins
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, Texas, USA
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10
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Asano R. The evolution of hierarchical structure building capacity for language and music: a bottom-up perspective. Primates 2021; 63:417-428. [PMID: 33839984 PMCID: PMC9463250 DOI: 10.1007/s10329-021-00905-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/26/2021] [Indexed: 12/27/2022]
Abstract
A central property of human language is its hierarchical structure. Humans can flexibly combine elements to build a hierarchical structure expressing rich semantics. A hierarchical structure is also considered as playing a key role in many other human cognitive domains. In music, auditory-motor events are combined into hierarchical pitch and/or rhythm structure expressing affect. How did such a hierarchical structure building capacity evolve? This paper investigates this question from a bottom-up perspective based on a set of action-related components as a shared basis underlying cognitive capacities of nonhuman primates and humans. Especially, I argue that the evolution of hierarchical structure building capacity for language and music is tractable for comparative evolutionary study once we focus on the gradual elaboration of shared brain architecture: the cortico-basal ganglia-thalamocortical circuits for hierarchical control of goal-directed action and the dorsal pathways for hierarchical internal models. I suggest that this gradual elaboration of the action-related brain architecture in the context of vocal control and tool-making went hand in hand with amplification of working memory, and made the brain ready for hierarchical structure building in language and music.
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Affiliation(s)
- Rie Asano
- Systematic Musicology, Institute of Musicology, University of Cologne, Cologne, Germany.
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11
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Spocter MA, Sherwood CC, Schapiro SJ, Hopkins WD. Reproducibility of leftward planum temporale asymmetries in two genetically isolated populations of chimpanzees ( Pan troglodytes). Proc Biol Sci 2020; 287:20201320. [PMID: 32900313 PMCID: PMC7542794 DOI: 10.1098/rspb.2020.1320] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/17/2020] [Indexed: 12/23/2022] Open
Abstract
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. Studies in humans suggest that there is heritability of brain asymmetries of the PT, but this has not been explored to any extent in chimpanzees. Furthermore, the potential influence of non-genetic factors has raised questions about the reproducibility of earlier observations of PT asymmetry reported in chimpanzees. As such, the present study was aimed at examining both the heritability of phenotypic asymmetries in PT morphology, as well as their reproducibility. Using magnetic resonance imaging, we evaluated morphological asymmetries of PT surface area (mm2) and mean depth (mm) in captive chimpanzees (n = 291) derived from two genetically isolated populations. Our results confirm that chimpanzees exhibit a significant population-level leftward asymmetry for PT surface area, as well as significant heritability in the surface area and mean depth of the PT. These results conclusively demonstrate the existence of a leftward bias in PT asymmetry in chimpanzees and suggest that genetic mechanisms play a key role in the emergence of anatomical asymmetry in this region.
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Affiliation(s)
- Muhammad A. Spocter
- Department of Anatomy, Des Moines University, 3200 Grand Avenue, Des Moines, IA 50312, USA
- School of Anatomical Sciences, University of Witwatersrand, Johannesburg 2094, South Africa
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | - Steven J. Schapiro
- Department of Comparative Medicine, UT MD Anderson Cancer Center Bastrop, TX 78602, USA
- Department of Experimental Medicine, University of Copenhagen, Copenhagen, Denmark
| | - William D. Hopkins
- Department of Comparative Medicine, UT MD Anderson Cancer Center Bastrop, TX 78602, USA
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12
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The role of early social rearing, neurological, and genetic factors on individual differences in mutual eye gaze among captive chimpanzees. Sci Rep 2020; 10:7412. [PMID: 32366881 PMCID: PMC7198555 DOI: 10.1038/s41598-020-64051-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/09/2020] [Indexed: 02/06/2023] Open
Abstract
Mutual eye gaze plays an important role in primate social development and communication. In the current study, we examined the underlying experiential, genetic, and neuroanatomical basis of mutual eye gaze variation in adult captive chimpanzees. A multivariate analysis of variance revealed a significant rearing effect on bout length, with human-reared chimpanzees engaging in longer bouts of mutual gaze compared to mother-reared and wild-born individuals. Next, we utilized source-based morphometry (SBM) to examine gray matter covariation in magnetic resonance imaging scans and determine the relationship between the resulting gray matter covariation components and mutual eye gaze. One SBM component was negatively correlated with gaze duration (nucleus accumbens and anterior insular cortex), while two components were positively correlated with bout length (posterior cingulate cortex, inferior occipital cortex, middle temporal cortex, hippocampus, and the precentral sulcus). Finally, heritability analyses revealed mutual eye gaze to be modestly heritable and significant genetic correlations between bout length and two gray matter covariation components. This study reveals that non-genetic factors, and to a lesser extent, genetic factors appear to influence mutual eye gaze in adult chimpanzees, and is the first to report neuroanatomical correlates of mutual eye gaze variation in chimpanzees.
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13
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DeCasien AR, Sherwood CC, Schapiro SJ, Higham JP. Greater variability in chimpanzee ( Pan troglodytes) brain structure among males. Proc Biol Sci 2020; 287:20192858. [PMID: 32315585 PMCID: PMC7211446 DOI: 10.1098/rspb.2019.2858] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/23/2020] [Indexed: 01/15/2023] Open
Abstract
Across the animal kingdom, males tend to exhibit more behavioural and morphological variability than females, consistent with the 'greater male variability hypothesis'. This may reflect multiple mechanisms operating at different levels, including selective mechanisms that produce and maintain variation, extended male development, and X chromosome effects. Interestingly, human neuroanatomy shows greater male variability, but this pattern has not been demonstrated in any other species. To address this issue, we investigated sex-specific neuroanatomical variability in chimpanzees by examining relative and absolute surface areas of 23 cortical sulci across 226 individuals (135F/91M), using permutation tests of the male-to-female variance ratio of residuals from MCMC generalized linear mixed models controlling for relatedness. We used these models to estimate sulcal size heritability, simulations to assess the significance of heritability, and Pearson correlations to examine inter-sulcal correlations. Our results show that: (i) male brain structure is relatively more variable; (ii) sulcal surface areas are heritable and therefore potentially subject to selection; (iii) males exhibit lower heritability values, possibly reflecting longer development; and (iv) males exhibit stronger inter-sulcal correlations, providing indirect support for sex chromosome effects. These results provide evidence that greater male neuroanatomical variability extends beyond humans, and suggest both evolutionary and developmental explanations for this phenomenon.
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Affiliation(s)
- Alex R. DeCasien
- Department of Anthropology, New York University, New York, NY, USA
- New York Consortium in Evolutionary Primatology, New York, NY, USA
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, USA
| | - Steven J. Schapiro
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA
- Department of Experimental Medicine, The University of Copenhagen, Copenhagen, Denmark
| | - James P. Higham
- Department of Anthropology, New York University, New York, NY, USA
- New York Consortium in Evolutionary Primatology, New York, NY, USA
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Mulholland MM, Navabpour SV, Mareno MC, Schapiro SJ, Young LJ, Hopkins WD. AVPR1A variation is linked to gray matter covariation in the social brain network of chimpanzees. GENES BRAIN AND BEHAVIOR 2020; 19:e12631. [PMID: 31894656 DOI: 10.1111/gbb.12631] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/01/2019] [Accepted: 12/11/2019] [Indexed: 12/27/2022]
Abstract
The vasopressin system has been implicated in the regulation of social behavior and cognition in humans, nonhuman primates and other social mammals. In chimpanzees, polymorphisms in the vasopressin V1a receptor gene (AVPR1A) have been associated with social dimensions of personality, as well as to responses to sociocommunicative cues and mirror self-recognition. Despite evidence of this association with social cognition and behavior, there is little research on the neuroanatomical correlates of AVPR1A variation. In the current study, we tested the association between AVPR1A polymorphisms in the RS3 promotor region and gray matter covariation in chimpanzees using magnetic resonance imaging and source-based morphometry. The analysis identified 13 independent brain components, three of which differed significantly in covariation between the two AVPR1A genotypes (DupB-/- and DupB+/-; P < .05). DupB+/- chimpanzees showed greater covariation in gray matter in the premotor and prefrontal cortex, basal forebrain, lunate and cingulate cortex, and lesser gray matter covariation in the superior temporal sulcus and postcentral sulcus. Some of these regions were previously found to differ in vasopressin and oxytocin neural fibers between nonhuman primates, and in AVPR1A gene expression in humans with different RS3 alleles. This is the first report of an association between AVPR1A and gray matter covariation in nonhuman primates, and specifically links an AVPR1A polymorphism to structural variation in the social brain network. These results further affirm the value of chimpanzees as a model species for investigating the relationship between genetic variation, brain structure and social cognition with relevance to psychiatric disorders, including autism.
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Affiliation(s)
- Michele M Mulholland
- Georgia State University, Atlanta, Georgia.,Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, Texas
| | | | - Mary C Mareno
- Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, Texas
| | - Steven J Schapiro
- Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, Texas.,University of Copenhagen, Copenhagen, Denmark
| | - Larry J Young
- Department of Psychiatry and Behavioral Sciences, Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - William D Hopkins
- Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, Texas
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Nagano A. Development of a control task for clarifying the neural mechanisms underlying tool-use behavior in rats ( Rattus norvegicus). MethodsX 2019; 6:2845-2854. [PMID: 31871918 PMCID: PMC6911953 DOI: 10.1016/j.mex.2019.11.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/25/2019] [Indexed: 11/25/2022] Open
Abstract
Hook-choice training without tool-use-specific factors can be performed as a control task. Prior tool-use training improved rats’ performance in experimental tests. Control task for rodents allows investigation of the neural mechanisms of tool-use.
Many studies on non-human animals have attempted to investigate the neural mechanisms underlying tool-use behavior. However, previous studies showed considerable non-tool-use-specific differences between tool-use and control tasks. The purpose of the present study was to develop a control training task for studies that investigate the neural mechanisms behind tool-use in rodents. Eight rats were subjected to control tasks which excluded tool-use-specific factors and consisted of training for hook-pulling and hook-choice tasks, as well as tool-choice tests which included tool-use specific factors and were similar to those in a previous study on rats. With the exception of one rat, the results of the hook-choice training showed that the previous study and the present study had similar difficulty levels. In the tool-choice tests of the present study, rats did not choose the functional tools over the non-functional tools when there was no contradiction between their appearance and functionality, which contrasted with the previous study on which this study was based on. These results suggest that the training task that excludes tool-use-specific factors can be appropriately utilized as a control task for studies investigating the neural mechanisms behind tool-use in animals and, potentially, in humans. Hook-choice training without tool-use-specific factors can be performed as a control task. Prior tool-use training improved rats’ performance in experimental tests. Control task for rodents allows investigation of the neural mechanisms of tool-use.
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Affiliation(s)
- Akane Nagano
- Organization for Research Initiatives and Development, Faculty of Psychology, Doshisha University, Japan
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