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Thorstensen JR, Henderson TT, Kavanagh JJ. Serotonergic and noradrenergic contributions to motor cortical and spinal motoneuronal excitability in humans. Neuropharmacology 2024; 242:109761. [PMID: 37838337 DOI: 10.1016/j.neuropharm.2023.109761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Animal models indicate that motor behaviour is shaped by monoamine neuromodulators released diffusely throughout the brain and spinal cord. As an alternative to conducting a single study to explore the effects of neuromodulators on the human motor system, we have identified and collated human experiments investigating motor effects of well-characterised drugs that act on serotonergic and noradrenergic networks. In doing so, we present strong neuropharmacology evidence that human motor pathways are affected by neuromodulators across both healthy and clinical populations, insight that cannot be determined from a single reductionist experiment. We have focused our review on the effects that monoaminergic drugs have on muscle responses to non-invasive stimulation of the motor cortex and peripheral nerves, and other closely related tests of motoneuron excitability, and discuss how these measurement techniques elucidate the effects of neuromodulators at motor cortical and spinal motoneuronal levels. Although there is some heterogeneity in study methods, we find drugs acting to enhance extracellular concentrations of serotonin tend to reduce the excitability of the human motor cortex, and enhanced extracellular concentrations of noradrenaline increases motor cortical excitability by enhancing intracortical facilitation and reducing inhibition. Both monoamines tend to enhance the excitability of spinal motoneurons. Overall, this review details the importance of neuromodulators for the output of human motor pathways and suggests that commonly prescribed monoaminergic drugs target the motor system in addition to their typical psychiatric/neurological indications.
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Affiliation(s)
- Jacob R Thorstensen
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.
| | - Tyler T Henderson
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
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2
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Stimpson CD, Smaers JB, Raghanti MA, Phillips KA, Jacobs B, Hopkins WD, Hof PR, Sherwood CC. Evolutionary scaling and cognitive correlates of primate frontal cortex microstructure. Brain Struct Funct 2023:10.1007/s00429-023-02719-7. [PMID: 37889302 DOI: 10.1007/s00429-023-02719-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 10/02/2023] [Indexed: 10/28/2023]
Abstract
Investigating evolutionary changes in frontal cortex microstructure is crucial to understanding how modifications of neuron and axon distributions contribute to phylogenetic variation in cognition. In the present study, we characterized microstructural components of dorsolateral prefrontal cortex, orbitofrontal cortex, and primary motor cortex from 14 primate species using measurements of neuropil fraction and immunohistochemical markers for fast-spiking inhibitory interneurons, large pyramidal projection neuron subtypes, serotonergic innervation, and dopaminergic innervation. Results revealed that the rate of evolutionary change was similar across these microstructural variables, except for neuropil fraction, which evolves more slowly and displays the strongest correlation with brain size. We also found that neuropil fraction in orbitofrontal cortex layers V-VI was associated with cross-species variation in performance on experimental tasks that measure self-control. These findings provide insight into the evolutionary reorganization of the primate frontal cortex in relation to brain size scaling and its association with cognitive processes.
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Affiliation(s)
- Cheryl D Stimpson
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, USA
- DoD/USU Brain Tissue Repository and Neuropathology Program, Uniformed Services University (USU), Bethesda, MD, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, MD, USA
| | - Jeroen B Smaers
- Department of Anthropology, Stony Brook University, Stony Brook, NY, USA
| | - Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Kimberley A Phillips
- Department of Psychology, Trinity University, San Antonio, TX, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Bob Jacobs
- Department of Psychology, Laboratory of Quantitative Neuromorphology, Colorado College, Colorado Springs, CO, USA
| | - William D Hopkins
- Department of Comparative Medicine, Michale E Keeling Center for Comparative Medicine and Research, M D Anderson Cancer Center, Bastrop, TX, USA
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Center for Discovery and Innovation, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 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.
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3
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Schmidt ERE, Polleux F. Genetic Mechanisms Underlying the Evolution of Connectivity in the Human Cortex. Front Neural Circuits 2022; 15:787164. [PMID: 35069126 PMCID: PMC8777274 DOI: 10.3389/fncir.2021.787164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/09/2021] [Indexed: 12/22/2022] Open
Abstract
One of the most salient features defining modern humans is our remarkable cognitive capacity, which is unrivaled by any other species. Although we still lack a complete understanding of how the human brain gives rise to these unique abilities, the past several decades have witnessed significant progress in uncovering some of the genetic, cellular, and molecular mechanisms shaping the development and function of the human brain. These features include an expansion of brain size and in particular cortical expansion, distinct physiological properties of human neurons, and modified synaptic development. Together they specify the human brain as a large primate brain with a unique underlying neuronal circuit architecture. Here, we review some of the known human-specific features of neuronal connectivity, and we outline how novel insights into the human genome led to the identification of human-specific genetic modifiers that played a role in the evolution of human brain development and function. Novel experimental paradigms are starting to provide a framework for understanding how the emergence of these human-specific genomic innovations shaped the structure and function of neuronal circuits in the human brain.
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Affiliation(s)
- Ewoud R. E. Schmidt
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
- *Correspondence: Ewoud R. E. Schmidt
| | - Franck Polleux
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
- Kavli Institute for Brain Science, Columbia University, New York, NY, United States
- Franck Polleux
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4
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Preuss TM, Wise SP. Evolution of prefrontal cortex. Neuropsychopharmacology 2022; 47:3-19. [PMID: 34363014 PMCID: PMC8617185 DOI: 10.1038/s41386-021-01076-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/01/2021] [Accepted: 06/15/2021] [Indexed: 02/07/2023]
Abstract
Subdivisions of the prefrontal cortex (PFC) evolved at different times. Agranular parts of the PFC emerged in early mammals, and rodents, primates, and other modern mammals share them by inheritance. These are limbic areas and include the agranular orbital cortex and agranular medial frontal cortex (areas 24, 32, and 25). Rodent research provides valuable insights into the structure, functions, and development of these shared areas, but it contributes less to parts of the PFC that are specific to primates, namely, the granular, isocortical PFC that dominates the frontal lobe in humans. The first granular PFC areas evolved either in early primates or in the last common ancestor of primates and tree shrews. Additional granular PFC areas emerged in the primate stem lineage, as represented by modern strepsirrhines. Other granular PFC areas evolved in simians, the group that includes apes, humans, and monkeys. In general, PFC accreted new areas along a roughly posterior to anterior trajectory during primate evolution. A major expansion of the granular PFC occurred in humans in concert with other association areas, with modifications of corticocortical connectivity and gene expression, although current evidence does not support the addition of a large number of new, human-specific PFC areas.
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Affiliation(s)
- Todd M Preuss
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA.
| | - Steven P Wise
- Olschefskie Institute for the Neurobiology of Knowledge, Bethesda, MD, 20814, USA
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Yokoyama C, Autio JA, Ikeda T, Sallet J, Mars RB, Van Essen DC, Glasser MF, Sadato N, Hayashi T. Comparative connectomics of the primate social brain. Neuroimage 2021; 245:118693. [PMID: 34732327 PMCID: PMC9159291 DOI: 10.1016/j.neuroimage.2021.118693] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/27/2021] [Accepted: 10/29/2021] [Indexed: 01/13/2023] Open
Abstract
Social interaction is thought to provide a selection pressure for human intelligence, yet little is known about its neurobiological basis and evolution throughout the primate lineage. Recent advances in neuroimaging have enabled whole brain investigation of brain structure, function, and connectivity in humans and non-human primates (NHPs), leading to a nascent field of comparative connectomics. However, linking social behavior to brain organization across the primates remains challenging. Here, we review the current understanding of the macroscale neural mechanisms of social behaviors from the viewpoint of system neuroscience. We first demonstrate an association between the number of cortical neurons and the size of social groups across primates, suggesting a link between neural information-processing capacity and social capabilities. Moreover, by capitalizing on recent advances in species-harmonized functional MRI, we demonstrate that portions of the mirror neuron system and default-mode networks, which are thought to be important for representation of the other's actions and sense of self, respectively, exhibit similarities in functional organization in macaque monkeys and humans, suggesting possible homologies. With respect to these two networks, we describe recent developments in the neurobiology of social perception, joint attention, personality and social complexity. Together, the Human Connectome Project (HCP)-style comparative neuroimaging, hyperscanning, behavioral, and other multi-modal investigations are expected to yield important insights into the evolutionary foundations of human social behavior.
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Affiliation(s)
- Chihiro Yokoyama
- Laboratory for Brain Connectomics Imaging, RIKEN Center for Biosystems Dynamics Research, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan.
| | - Joonas A Autio
- Laboratory for Brain Connectomics Imaging, RIKEN Center for Biosystems Dynamics Research, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Takuro Ikeda
- Laboratory for Brain Connectomics Imaging, RIKEN Center for Biosystems Dynamics Research, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Jérôme Sallet
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, Oxford University, Oxford, United Kingdom; University of Lyon, Université Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - Rogier B Mars
- Wellcome Centre for Integrative Neuroimaging, Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom; Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - David C Van Essen
- Departments of Neuroscience, Washington University Medical School, St Louis, MO, United States of America
| | - Matthew F Glasser
- Departments of Neuroscience, Washington University Medical School, St Louis, MO, United States of America; Department of Radiology, Washington University Medical School, St Louis, MO, United States of America
| | - Norihiro Sadato
- National Institute for Physiological Sciences, Okazaki, Japan; The Graduate University for Advanced Studies (SOKENDAI), Kanagawa, Japan
| | - Takuya Hayashi
- Laboratory for Brain Connectomics Imaging, RIKEN Center for Biosystems Dynamics Research, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan; School of Medicine, Kyoto University, Kyoto, Japan.
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Senft RA, Dymecki SM. Neuronal pericellular baskets: neurotransmitter convergence and regulation of network excitability. Trends Neurosci 2021; 44:915-924. [PMID: 34565612 PMCID: PMC8551026 DOI: 10.1016/j.tins.2021.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/29/2021] [Accepted: 08/27/2021] [Indexed: 11/20/2022]
Abstract
A pericellular basket is a presynaptic configuration of numerous axonal boutons outlining a target neuron soma and its proximal dendrites. Recent studies show neurochemical diversity of pericellular baskets and suggest that neurotransmitter usage together with the dense, soma-proximal boutons may permit strong input effects on different timescales. Here we review the development, distribution, neurochemical phenotypes, and possible functions of pericellular baskets. As an example, we highlight pericellular baskets formed by projections of certain Pet1/Fev neurons of the serotonergic raphe nuclei. We propose that pericellular baskets represent convergence sites of competition or facilitation between neurotransmitter systems on downstream circuitry, especially in limbic brain regions, where pericellular baskets are widespread. Study of these baskets may enhance our understanding of monoamine regulation of memory, social behavior, and brain oscillations.
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Affiliation(s)
- Rebecca A Senft
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Susan M Dymecki
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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Patthy Á, Murai J, Hanics J, Pintér A, Zahola P, Hökfelt TGM, Harkany T, Alpár A. Neuropathology of the Brainstem to Mechanistically Understand and to Treat Alzheimer's Disease. J Clin Med 2021; 10:jcm10081555. [PMID: 33917176 PMCID: PMC8067882 DOI: 10.3390/jcm10081555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder as yet without effective therapy. Symptoms of this disorder typically reflect cortical malfunction with local neurohistopathology, which biased investigators to search for focal triggers and molecular mechanisms. Cortex, however, receives massive afferents from caudal brain structures, which do not only convey specific information but powerfully tune ensemble activity. Moreover, there is evidence that the start of AD is subcortical. The brainstem harbors monoamine systems, which establish a dense innervation in both allo- and neocortex. Monoaminergic synapses can co-release neuropeptides either by precisely terminating on cortical neurons or, when being “en passant”, can instigate local volume transmission. Especially due to its early damage, malfunction of the ascending monoaminergic system emerges as an early sign and possible trigger of AD. This review summarizes the involvement and cascaded impairment of brainstem monoaminergic neurons in AD and discusses cellular mechanisms that lead to their dysfunction. We highlight the significance and therapeutic challenges of transmitter co-release in ascending activating system, describe the role and changes of local connections and distant afferents of brainstem nuclei in AD, and summon the rapidly increasing diagnostic window during the last few years.
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Affiliation(s)
- Ágoston Patthy
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Murai
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Hanics
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
| | - Anna Pintér
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Péter Zahola
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Tomas G. M. Hökfelt
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
| | - Tibor Harkany
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
- Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, 1090 Vienna, Austria
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
- Correspondence:
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8
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Sauciuc GA, Persson T. Chimpanzees Predict the Hedonic Outcome of Novel Taste Combinations: The Evolutionary Origins of Affective Forecasting. Front Psychol 2020; 11:549193. [PMID: 33192796 PMCID: PMC7646213 DOI: 10.3389/fpsyg.2020.549193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 09/07/2020] [Indexed: 12/02/2022] Open
Abstract
Affective forecasting–predicting the emotional outcome of never-before experienced situations–is pervasive in our lives. When facing novel situations, we can quickly integrate bits and pieces of prior experiences to envisage possible scenarios and their outcomes, and what these might feel like. Such affective glimpses of the future often steer the decisions we make. By enabling principled decision-making in novel situations, affective forecasting confers the important adaptive advantage of eluding the potentially costly consequences of tackling such situations by trial-and-error. Affective forecasting has been hypothesized as uniquely human, yet, in a recent study we found suggestive evidence of this ability in an orangutan. To test non-verbal subjects, we capitalized on culinary examples of affective forecasting and devised a behavioral test that required the subjects to make predictions about novel juice mixes produced from familiar ingredients. In the present study, we administered the same task to two chimpanzees and found that their performance was comparable to that of the previously tested orangutan and 10 humans, who served as a comparison group. To improve the comparability of human and animal performance, in the present study we also introduced a new approach to assessing if the subjects’ performance was indicative of affective forecasting, which relies exclusively on behavioral data. The results of the study open for the possibility that affective forecasting has evolved in the common ancestor of the great apes, providing Hominids with the adaptive advantage of e.g., quickly evaluating heterogeneous food patches using hedonic prediction.
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Lew CH, Groeniger KM, Hanson KL, Cuevas D, Greiner DMZ, Hrvoj-Mihic B, Bellugi U, Schumann CM, Semendeferi K. Serotonergic innervation of the amygdala is increased in autism spectrum disorder and decreased in Williams syndrome. Mol Autism 2020; 11:12. [PMID: 32024554 PMCID: PMC7003328 DOI: 10.1186/s13229-019-0302-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/04/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Williams syndrome (WS) and autism spectrum disorder (ASD) are neurodevelopmental disorders that demonstrate overlapping genetic associations, dichotomous sociobehavioral phenotypes, and dichotomous pathological differences in neuronal distribution in key social brain areas, including the prefrontal cortex and the amygdala. The serotonergic system is critical to many processes underlying neurodevelopment and is additionally an important neuromodulator associated with behavioral variation. The amygdala is heavily innervated by serotonergic projections, suggesting that the serotonergic system is a significant mediator of neuronal activity. Disruptions to the serotonergic system, and atypical structure and function of the amygdala, are implicated in both WS and ASD. METHODS We quantified the serotonergic axon density in the four major subdivisions of the amygdala in the postmortem brains of individuals diagnosed with ASD and WS and neurotypical (NT) brains. RESULTS We found opposing directions of change in serotonergic innervation in the two disorders, with ASD displaying an increase in serotonergic axons compared to NT and WS displaying a decrease. Significant differences (p < 0.05) were observed between WS and ASD data sets across multiple amygdala nuclei. LIMITATIONS This study is limited by the availability of human postmortem tissue. Small sample size is an unavoidable limitation of most postmortem human brain research and particularly postmortem research in rare disorders. CONCLUSIONS Differential alterations to serotonergic innervation of the amygdala may contribute to differences in sociobehavioral phenotype in WS and ASD. These findings will inform future work identifying targets for future therapeutics in these and other disorders characterized by atypical social behavior.
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Affiliation(s)
- C H Lew
- Department of Anthropology, University of California, San Diego, USA
| | - K M Groeniger
- Department of Anthropology, University of California, San Diego, USA
| | - K L Hanson
- Department of Anthropology, University of California, San Diego, USA
| | - D Cuevas
- Department of Biological Sciences, University of California, San Diego, USA
| | - D M Z Greiner
- Department of Biological Sciences, University of California, San Diego, USA
| | - B Hrvoj-Mihic
- Department of Anthropology, University of California, San Diego, USA
| | - U Bellugi
- Salk Institute for Biological Sciences, San Diego, USA
| | - C M Schumann
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, the MIND Institute, Sacramento, USA
| | - K Semendeferi
- Department of Anthropology, University of California, San Diego, USA.
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Prodromidou K, Matsas R. Species-Specific miRNAs in Human Brain Development and Disease. Front Cell Neurosci 2019; 13:559. [PMID: 31920559 PMCID: PMC6930153 DOI: 10.3389/fncel.2019.00559] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 12/04/2019] [Indexed: 12/20/2022] Open
Abstract
Identification of the unique features of human brain development and function can be critical towards the elucidation of intricate processes such as higher cognitive functions and human-specific pathologies like neuropsychiatric and behavioral disorders. The developing primate and human central nervous system (CNS) are distinguished by expanded progenitor zones and a protracted time course of neurogenesis, leading to the expansion in brain size, prominent gyral anatomy, distinctive synaptic properties, and complex neural circuits. Comparative genomic studies have revealed that adaptations of brain capacities may be partly explained by human-specific genetic changes that impact the function of proteins associated with neocortical expansion, synaptic function, and language development. However, the formation of complex gene networks may be most relevant for brain evolution. Indeed, recent studies identified distinct human-specific gene expression patterns across developmental time occurring in brain regions linked to cognition. Interestingly, such modules show species-specific divergence and are enriched in genes associated with neuronal development and synapse formation whilst also being implicated in neuropsychiatric diseases. microRNAs represent a powerful component of gene-regulatory networks by promoting spatiotemporal post-transcriptional control of gene expression in the human and primate brain. It has also been suggested that the divergence in miRNA expression plays an important role in shaping gene expression divergence among species. Primate-specific and human-specific miRNAs are principally involved in progenitor proliferation and neurogenic processes but also associate with human cognition, and neurological disorders. Human embryonic or induced pluripotent stem cells and brain organoids, permitting experimental access to neural cells and differentiation stages that are otherwise difficult or impossible to reach in humans, are an essential means for studying species-specific brain miRNAs. Single-cell sequencing approaches can further decode refined miRNA-mRNA interactions during developmental transitions. Elucidating species-specific miRNA regulation will shed new light into the mechanisms that control spatiotemporal events during human brain development and disease, an important step towards fostering novel, holistic and effective therapeutic approaches for neural disorders. In this review, we discuss species-specific regulation of miRNA function, its contribution to the evolving features of the human brain and in neurological disease, with respect also to future therapeutic approaches.
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Affiliation(s)
- Kanella Prodromidou
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
| | - Rebecca Matsas
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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11
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Sato DX, Ishii Y, Nagai T, Ohashi K, Kawata M. Human-specific mutations in VMAT1 confer functional changes and multi-directional evolution in the regulation of monoamine circuits. BMC Evol Biol 2019; 19:220. [PMID: 31791232 PMCID: PMC6889191 DOI: 10.1186/s12862-019-1543-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 11/15/2019] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Neurochemicals like serotonin and dopamine play crucial roles in human cognitive and emotional functions. Vesicular monoamine transporter 1 (VMAT1) transports monoamine neurotransmitters, and its variant (136Thr) is associated with various psychopathological symptoms and reduced monoamine uptake relative to 136Ile. We previously showed that two human-specific amino acid substitutions (Glu130Gly and Asn136Thr/Ile) of VMAT1 were subject to positive natural selection. However, the potential functional alterations caused by these substitutions (Glu130Gly and Asn136Thr) remain unclear. To assess functional changes in VMAT1 from an evolutionary perspective, we reconstructed ancestral residues and examined the role of these substitutions in monoamine uptake in vitro using fluorescent false neurotransmitters (FFN), which are newly developed substances used to quantitatively assay VMATs. RESULTS Immunoblotting confirmed that all the transfected YFP-VMAT1 variants are properly expressed in HEK293T cells at comparable levels, and no significant difference was seen in the density and the size of vesicles among them. Our fluorescent assays revealed a significant difference in FFN206 uptake among VMAT1 variants: 130Glu/136Asn, 130Glu/136Thr, and 130Gly/136Ile showed significantly higher levels of FFN206 uptake than 130Gly/136Asn and 130Gly/136Thr, indicating that both 130Glu and 136Ile led to increased neurotransmitter uptake, for which 136Thr and 136Asn were comparable by contrast. CONCLUSIONS These findings suggest that monoamine uptake by VMAT1 initially declined (from 130Glu/136Asn to 130Gly/136Thr) in human evolution, possibly resulting in higher susceptibility to the external environment of our ancestors.
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Affiliation(s)
- Daiki X Sato
- Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Yuu Ishii
- Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Tomoaki Nagai
- Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Kazumasa Ohashi
- Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Masakado Kawata
- Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan.
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12
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Identification, characterization, and expression analysis of a serotonin receptor involved in the reproductive process of the Pacific abalone, Haliotis discus hannai. Mol Biol Rep 2019; 47:555-567. [PMID: 31696430 DOI: 10.1007/s11033-019-05162-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/23/2019] [Indexed: 10/25/2022]
Abstract
Serotonin receptor (5-HT) is a biogenic amine acting as a neurotransmitter and neuromodulator that mediates various aspects of reproduction and gametogenesis. The full-length nucleotide sequence of Haliotis discus hannai encodes a protein of 417 amino acids with a predicted molecular mass of 46.54 kDa and isoelectric point of 8.94. The structural profile of 5-HTHdh displayed key features of G protein-coupled receptors, including seven hydrophobic transmembrane domains, putative N-linked glycosylation sites, and several phosphorylation consensus motifs. It shares the highest homology of its amino acid sequence with the 5-HT receptor from Haliotis asinina, and to lesser extent of human 5-HT receptor. The cloned sequence possesses two cysteine residues (Cys-115 and Cys-193), which are likely to form a disulfide bond. Phylogenetic comparison with other known 5-HT receptor genes revealed that the 5-HTHdh is most closely related to the 5-HTHa receptor. The three-dimensional structure of the 5-HTHdh showed multiple alpha helices which is separated by a helix-loop-helix (HLH) structure. Quantitative PCR demonstrated that the receptor mRNA was predominantly expressed in the pleuropedal ganglion. Significant differences in the transcriptional activity of the 5-HTHdh gene were observed in the ovary at the ripening stage. An exclusive expression was detected in pleuropedal ganglion, testis, and ovary at higher effective accumulative temperature (1000 °C). In situ hybridization showed that the 5-HTHdh expressing neurosecretory cells were distributed in the cortex of the pleuropedal ganglion. Our results suggest that 5-HTHdh synthesized in the neural ganglia may be involved in oocyte maturation and spawning of H. discus hannai.
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Lew CH, Hanson KL, Groeniger KM, Greiner D, Cuevas D, Hrvoj-Mihic B, Schumann CM, Semendeferi K. Serotonergic innervation of the human amygdala and evolutionary implications. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 170:351-360. [PMID: 31260092 DOI: 10.1002/ajpa.23896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 01/09/2023]
Abstract
OBJECTIVES The serotonergic system is involved in the regulation of socio-emotional behavior and heavily innervates the amygdala, a key structure of social brain circuitry. We quantified serotonergic axon density of the four major nuclei of the amygdala in humans, and examined our results in light of previously published data sets in chimpanzees and bonobos. MATERIALS AND METHODS Formalin-fixed postmortem tissue sections of the amygdala from six humans were stained for serotonin transporter (SERT) utilizing immunohistochemistry. SERT-immunoreactive (ir) axon fiber density in the lateral, basal, accessory basal, and central nuclei of the amygdala was quantified using unbiased stereology. Nonparametric statistical analyses were employed to examine differences in SERT-ir axon density between amygdaloid nuclei within humans, as well as differences between humans and previously published data in chimpanzees and bonobos. RESULTS Humans displayed a unique pattern of serotonergic innervation of the amygdala, and SERT-ir axon density was significantly greater in the central nucleus compared to the lateral nucleus. SERT-ir axon density was significantly greater in humans compared to chimpanzees in the basal, accessory basal, and central nuclei. SERT-ir axon density was greater in humans compared to bonobos in the accessory basal and central nuclei. CONCLUSIONS The human pattern of SERT-ir axon distribution in the amygdala complements the redistribution of neurons in the amygdala in human evolution. The present findings suggest that differential serotonergic modulation of cognitive and autonomic pathways in the amygdala in humans, bonobos, and chimpanzees may contribute to species-level differences in social behavior.
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Affiliation(s)
- Caroline H Lew
- Department of Anthropology, University of California, San Diego, California
| | - Kari L Hanson
- Department of Anthropology, University of California, San Diego, California
| | | | - Demi Greiner
- Department of Biological Sciences, University of California, San Diego, California
| | - Deion Cuevas
- Department of Biological Sciences, University of California, San Diego, California
| | - Branka Hrvoj-Mihic
- Department of Anthropology, University of California, San Diego, California
| | - Cynthia M Schumann
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, The MIND Institute, Sacramento, California
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Kreutz A, Barger N. Maximizing Explanatory Power in Stereological Data Collection: A Protocol for Reliably Integrating Optical Fractionator and Multiple Immunofluorescence Techniques. Front Neuroanat 2018; 12:73. [PMID: 30425623 PMCID: PMC6218486 DOI: 10.3389/fnana.2018.00073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 08/20/2018] [Indexed: 11/21/2022] Open
Abstract
With the promise of greater reliability and replicability of estimates, stereological techniques have revolutionized data collection in the neurosciences. At the same time, improvements in immunohistochemistry and fluorescence imaging technologies have facilitated easy application of immunofluorescence protocols, allowing for isolation of multiple target proteins in one tissue sample. Combining multiple immunofluorescence labeling with stereological data collection can provide a powerful tool to maximize explanatory power and efficiency, while minimizing tissue use. Multiple cell classes, subtypes of larger populations, or different cell states can be quantified in one case and even in one sampling run. Here, we present a protocol integrating stereological data collection and multiple immunofluorescence using commonly employed widefield epifluorescence filter sets, optimized for blue (DAPI), green (FITC), and far red (CY5) channels. Our stereological protocol has been designed to accommodate the challenges of fluorescence imaging to overcome limitations like fixed filter sets, photobleaching, and uneven immunolabeling. To enhance fluorescence signal for stereological sampling, our immunolabeling protocol utilizes both high temperature antigen retrieval to improve primary antibody binding and secondary antibodies conjugated to optimally stable fluorophores. To illustrate the utility of this approach, we estimated the number of Ctip2 immunoreactive subcerebral projection neurons and NeuN immunoreactive neurons in rat cerebral cortex at postnatal day 10. We used DAPI (blue) to define the neocortex, anti-NeuN (far red) to identify neurons, and co-labeling of anti-Ctip2 (green) and anti-NeuN (far red) to isolate only subcerebral projection neurons. Our protocol resulted in estimates with low sampling error (CE < 0.05) and high intrarater reliability (ICC > 0.98) that fall within the range of published values, attesting to its efficacy. We show our immunofluorescence techniques can be used to reliably identify other cell types, e.g., different glial cell classes, to highlight the broader applications of our approach. The flexibility of the technique, increasingly reduced costs of fluorescence technologies, and savings in experimental time and tissue use make this approach valuable for neuroscientists interested in incorporating stereology to ask precise neurophysiological and neuroanatomical questions.
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Affiliation(s)
- Anna Kreutz
- Neuroscience Graduate Program, University of California, Davis, Davis, CA, United States
| | - Nicole Barger
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento, CA, United States
- MIND Institute, University of California, Davis, Sacramento, CA, United States
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15
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Sousa AMM, Meyer KA, Santpere G, Gulden FO, Sestan N. Evolution of the Human Nervous System Function, Structure, and Development. Cell 2017; 170:226-247. [PMID: 28708995 DOI: 10.1016/j.cell.2017.06.036] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 04/21/2017] [Accepted: 06/22/2017] [Indexed: 12/22/2022]
Abstract
The nervous system-in particular, the brain and its cognitive abilities-is among humans' most distinctive and impressive attributes. How the nervous system has changed in the human lineage and how it differs from that of closely related primates is not well understood. Here, we consider recent comparative analyses of extant species that are uncovering new evidence for evolutionary changes in the size and the number of neurons in the human nervous system, as well as the cellular and molecular reorganization of its neural circuits. We also discuss the developmental mechanisms and underlying genetic and molecular changes that generate these structural and functional differences. As relevant new information and tools materialize at an unprecedented pace, the field is now ripe for systematic and functionally relevant studies of the development and evolution of human nervous system specializations.
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Affiliation(s)
- André M M Sousa
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Kyle A Meyer
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Gabriel Santpere
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Forrest O Gulden
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA; Department of Genetics, Yale School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA; Section of Comparative Medicine, Yale School of Medicine, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, CT, USA; Yale Child Study Center, Yale School of Medicine, New Haven, CT, USA; Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA.
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16
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Rajkowska G, Mahajan G, Legutko B, Challagundla L, Griswold M, Albert PR, Daigle M, Miguel-Hidalgo JJ, Austin MC, Blakely RD, Steffens DC, Stockmeier CA. Length of axons expressing the serotonin transporter in orbitofrontal cortex is lower with age in depression. Neuroscience 2017; 359:30-39. [PMID: 28711621 DOI: 10.1016/j.neuroscience.2017.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 06/08/2017] [Accepted: 07/04/2017] [Indexed: 12/27/2022]
Abstract
Studies of major depressive disorder (MDD) in postmortem brain tissue report enhanced binding to inhibitory serotonin-1A autoreceptors in midbrain dorsal raphe and reductions in length of axons expressing the serotonin transporter (SERT) in dorsolateral prefrontal cortex. The length density of axons expressing SERT in the orbitofrontal cortex (OFC) was determined in 18 subjects with MDD and 17 age-matched control subjects. A monoclonal antibody was used to immunohistochemically label the SERT in fixed sections of OFC. The 3-dimensional length density of SERT-immunoreactive (ir) axons in layer VI of OFC was estimated. The age of subjects with MDD was negatively correlated with SERT axon length (r=-0.77, p<0.0005). The significant effect of age persisted when removing four depressed subjects with an antidepressant medication present at the time of death, or when removing nine depressed subjects that had a recent prescription for an antidepressant medication. Neither gender, tissue pH, postmortem interval, 5-HTTLPR genotype, time in fixative, nor death by suicide had a significant effect on axon length. The age-related decrease in SERT-ir axon length in MDD may reflect pathology of ascending axons passing through deep white matter hyperintensities. Greater length of axons expressing SERT in younger subjects with MDD may result in a significant deficit in serotonin availability in OFC.
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Affiliation(s)
- Grazyna Rajkowska
- Department of Psychiatry and Human Behavior, School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Gouri Mahajan
- Department of Psychiatry and Human Behavior, School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Beata Legutko
- Department of Psychiatry and Human Behavior, School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Lavanya Challagundla
- Department of Data Science, JD Bower School of Population Health, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Michael Griswold
- Department of Data Science, JD Bower School of Population Health, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Paul R Albert
- Ottawa Hospital Research Institute (Neuroscience) and UOttawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada.
| | - Mireille Daigle
- Ottawa Hospital Research Institute (Neuroscience) and UOttawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada.
| | - Jose J Miguel-Hidalgo
- Department of Psychiatry and Human Behavior, School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Mark C Austin
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA.
| | - Randy D Blakely
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - David C Steffens
- Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT 06030, USA.
| | - Craig A Stockmeier
- Department of Psychiatry and Human Behavior, School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA; Department of Psychiatry, Case Western Reserve University, Cleveland, OH 44106, USA.
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17
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Glausier JR, Roberts RC, Lewis DA. Ultrastructural analysis of parvalbumin synapses in human dorsolateral prefrontal cortex. J Comp Neurol 2017; 525:2075-2089. [PMID: 28074478 PMCID: PMC5397325 DOI: 10.1002/cne.24171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 12/11/2022]
Abstract
Coordinated activity of neural circuitry in the primate dorsolateral prefrontal cortex (DLPFC) supports a range of cognitive functions. Altered DLPFC activation is implicated in a number of human psychiatric and neurological illnesses. Proper DLPFC activity is, in part, maintained by two populations of neurons containing the calcium-binding protein parvalbumin (PV): local inhibitory interneurons that form Type II synapses, and long-range glutamatergic inputs from the thalamus that form Type I synapses. Understanding the contributions of each PV neuronal population to human DLPFC function requires a detailed examination of their anatomical properties. Consequently, we performed an electron microscopic analysis of (1) the distribution of PV immunoreactivity within the neuropil, (2) the properties of dendritic shafts of PV-IR interneurons, (3) Type II PV-IR synapses from PV interneurons, and (4) Type I PV-IR synapses from long-range projections, within the superficial and middle laminar zones of the human DLPFC. In both laminar zones, Type II PV-IR synapses from interneurons comprised ∼60% of all PV-IR synapses, and Type I PV-IR synapses from putative thalamocortical terminals comprised the remaining ∼40% of PV-IR synapses. Thus, the present study suggests that innervation from PV-containing thalamic nuclei extends across superficial and middle layers of the human DLPFC. These findings contrast with previous ultrastructural studies in monkey DLPFC where Type I PV-IR synapses were not identified in the superficial laminar zone. The presumptive added modulation of DLPFC circuitry by the thalamus in human may contribute to species-specific, higher-order functions.
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Affiliation(s)
- Jill R. Glausier
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - Rosalinda C. Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - David A. Lewis
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
- Department of Neuroscience, University of Pittsburgh School of Arts and Sciences, Pittsburgh, PA 15213
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18
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Šimić G, Babić Leko M, Wray S, Harrington CR, Delalle I, Jovanov-Milošević N, Bažadona D, Buée L, de Silva R, Di Giovanni G, Wischik CM, Hof PR. Monoaminergic neuropathology in Alzheimer's disease. Prog Neurobiol 2017; 151:101-138. [PMID: 27084356 PMCID: PMC5061605 DOI: 10.1016/j.pneurobio.2016.04.001] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/09/2016] [Accepted: 04/05/2016] [Indexed: 01/02/2023]
Abstract
None of the proposed mechanisms of Alzheimer's disease (AD) fully explains the distribution patterns of the neuropathological changes at the cellular and regional levels, and their clinical correlates. One aspect of this problem lies in the complex genetic, epigenetic, and environmental landscape of AD: early-onset AD is often familial with autosomal dominant inheritance, while the vast majority of AD cases are late-onset, with the ε4 variant of the gene encoding apolipoprotein E (APOE) known to confer a 5-20 fold increased risk with partial penetrance. Mechanisms by which genetic variants and environmental factors influence the development of AD pathological changes, especially neurofibrillary degeneration, are not yet known. Here we review current knowledge of the involvement of the monoaminergic systems in AD. The changes in the serotonergic, noradrenergic, dopaminergic, histaminergic, and melatonergic systems in AD are briefly described. We also summarize the possibilities for monoamine-based treatment in AD. Besides neuropathologic AD criteria that include the noradrenergic locus coeruleus (LC), special emphasis is given to the serotonergic dorsal raphe nucleus (DRN). Both of these brainstem nuclei are among the first to be affected by tau protein abnormalities in the course of sporadic AD, causing behavioral and cognitive symptoms of variable severity. The possibility that most of the tangle-bearing neurons of the LC and DRN may release amyloid β as well as soluble monomeric or oligomeric tau protein trans-synaptically by their diffuse projections to the cerebral cortex emphasizes their selective vulnerability and warrants further investigations of the monoaminergic systems in AD.
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Affiliation(s)
- Goran Šimić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia.
| | - Mirjana Babić Leko
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Selina Wray
- Reta Lila Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | - Ivana Delalle
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Nataša Jovanov-Milošević
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Danira Bažadona
- Department of Neurology, University Hospital Center Zagreb, Zagreb, Croatia
| | - Luc Buée
- University of Lille, Inserm, CHU-Lille, UMR-S 1172, Alzheimer & Tauopathies, Lille, France
| | - Rohan de Silva
- Reta Lila Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Claude M Wischik
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Patrick R Hof
- Fishberg Department of Neuroscience, Ronald M. Loeb Center for Alzheimer's Disease, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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19
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20
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Raab K, Kirsch P, Mier D. Understanding the impact of 5-HTTLPR, antidepressants, and acute tryptophan depletion on brain activation during facial emotion processing: A review of the imaging literature. Neurosci Biobehav Rev 2016; 71:176-197. [DOI: 10.1016/j.neubiorev.2016.08.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/28/2016] [Accepted: 08/26/2016] [Indexed: 12/22/2022]
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21
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Stephenson AR, Edler MK, Erwin JM, Jacobs B, Hopkins WD, Hof PR, Sherwood CC, Raghanti MA. Cholinergic innervation of the basal ganglia in humans and other anthropoid primates. J Comp Neurol 2016; 525:319-332. [DOI: 10.1002/cne.24067] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 06/06/2016] [Accepted: 06/14/2016] [Indexed: 12/16/2022]
Affiliation(s)
| | - Melissa K. Edler
- School of Biomedical Sciences; Kent State University; Kent Ohio 44242
| | - Joseph M. Erwin
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology; The George Washington University; Washington DC 20052
- Behavioral Health Services Department, California National Primate Research Center; University of California; Davis California 95616
| | - Bob Jacobs
- Laboratory of Quantitative Neuromorphology, Department of Psychology; Colorado College; Colorado Springs Colorado 80903
| | - William D. Hopkins
- Neuroscience Institute and Language Research Center; Georgia State University; Atlanta Georgia 30322
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute; Icahn School of Medicine at Mount Sinai; New York New York 10029
- New York Consortium in Evolutionary Primatology; New York New York 10024
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology; The George Washington University; Washington DC 20052
| | - Mary Ann Raghanti
- Department of Anthropology; Kent State University; Kent Ohio 44242
- School of Biomedical Sciences; Kent State University; Kent Ohio 44242
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22
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Raghanti MA, Edler MK, Stephenson AR, Wilson LJ, Hopkins WD, Ely JJ, Erwin JM, Jacobs B, Hof PR, Sherwood CC. Human-specific increase of dopaminergic innervation in a striatal region associated with speech and language: A comparative analysis of the primate basal ganglia. J Comp Neurol 2016; 524:2117-29. [PMID: 26715195 PMCID: PMC4860035 DOI: 10.1002/cne.23937] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 11/22/2015] [Indexed: 01/08/2023]
Abstract
The dopaminergic innervation of the striatum has been implicated in learning processes and in the development of human speech and language. Several lines of evidence suggest that evolutionary changes in dopaminergic afferents of the striatum may be associated with uniquely human cognitive and behavioral abilities, including the association of the human-specific sequence of the FOXP2 gene with decreased dopamine in the dorsomedial striatum of mice. To examine this possibility, we quantified the density of tyrosine hydroxylase-immunoreactive axons as a measure of dopaminergic innervation within five basal ganglia regions in humans, great apes, and New and Old World monkeys. Our results indicate that humans differ from nonhuman primate species in having a significant increase in dopaminergic innervation selectively localized to the medial caudate nucleus. This region of the striatum is highly interconnected, receiving afferents from multiple neocortical regions, and supports behavioral and cognitive flexibility. The medial caudate nucleus also shows hyperactivity in humans lacking a functional FOXP2 allele and exhibits altered dopamine concentrations in humanized Foxp2 mice. Additionally, striatal dopaminergic input was not altered in chimpanzees that used socially learned attention-getting sounds versus those that did not. This evidence indicates that the increase in dopamine innervation of the medial caudate nucleus in humans is a species-typical characteristic not associated with experience-dependent plasticity. The specificity of this increase may be related to the degree of convergence from cortical areas within this region of the striatum and may also be involved in human speech and language. J. Comp. Neurol. 524:2117-2129, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology, Kent State University, Kent, OH 44242, USA
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Melissa K. Edler
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | | | - Lakaléa J. Wilson
- Department of Anthropology, Kent State University, Kent, OH 44242, USA
| | - William D. Hopkins
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322, USA
| | | | - Joseph M. Erwin
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052 USA
- California National Primate Research Center, University of California, Davis
| | - Bob Jacobs
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado College, Colorado Springs, CO 80903, USA
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- New York Consortium in Evolutionary Primatology, New York, NY 10024, USA
| | - Chet C. Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052 USA
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23
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Latzman RD, Taglialatela JP, Hopkins WD. Delay of gratification is associated with white matter connectivity in the dorsal prefrontal cortex: a diffusion tensor imaging study in chimpanzees (Pan troglodytes). Proc Biol Sci 2016; 282:20150764. [PMID: 26041344 DOI: 10.1098/rspb.2015.0764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Individual variability in delay of gratification (DG) is associated with a number of important outcomes in both non-human and human primates. Using diffusion tensor imaging (DTI), this study describes the relationship between probabilistic estimates of white matter tracts projecting from the caudate to the prefrontal cortex (PFC) and DG abilities in a sample of 49 captive chimpanzees (Pan troglodytes). After accounting for time between collection of DTI scans and DG measurement, age and sex, higher white matter connectivity between the caudate and right dorsal PFC was found to be significantly associated with the acquisition (i.e. training phase) but not the maintenance of DG abilities. No other associations were found to be significant. The integrity of white matter connectivity between regions of the striatum and the PFC appear to be associated with inhibitory control in chimpanzees, with perturbations on this circuit potentially leading to a variety of maladaptive outcomes. Additionally, results have potential translational implications for understanding the pathophysiology of a number of psychiatric and clinical outcomes in humans.
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Affiliation(s)
- Robert D Latzman
- Department of Psychology, Georgia State University, Atlanta, GA, USA
| | - Jared P Taglialatela
- Department of Biology and Physics, Kennesaw State University, Kennesaw, GA, USA Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - William D Hopkins
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA
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24
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Stimpson CD, Barger N, Taglialatela JP, Gendron-Fitzpatrick A, Hof PR, Hopkins WD, Sherwood CC. Differential serotonergic innervation of the amygdala in bonobos and chimpanzees. Soc Cogn Affect Neurosci 2015; 11:413-22. [PMID: 26475872 DOI: 10.1093/scan/nsv128] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/07/2015] [Indexed: 01/18/2023] Open
Abstract
Humans' closest living relatives are bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), yet these great ape species differ considerably from each other in terms of social behavior. Bonobos are more tolerant of conspecifics in competitive contexts and often use sexual behavior to mediate social interactions. Chimpanzees more frequently employ aggression during conflicts and actively patrol territories between communities. Regulation of emotional responses is facilitated by the amygdala, which also modulates social decision-making, memory and attention. Amygdala responsiveness is further regulated by the neurotransmitter serotonin. We hypothesized that the amygdala of bonobos and chimpanzees would differ in its neuroanatomical organization and serotonergic innervation. We measured volumes of regions and the length density of serotonin transporter-containing axons in the whole amygdala and its lateral, basal, accessory basal and central nuclei. Results showed that accessory basal nucleus volume was larger in chimpanzees than in bonobos. Of particular note, the amygdala of bonobos had more than twice the density of serotonergic axons than chimpanzees, with the most pronounced differences in the basal and central nuclei. These findings suggest that variation in serotonergic innervation of the amygdala may contribute to mediating the remarkable differences in social behavior exhibited by bonobos and chimpanzees.
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Affiliation(s)
- Cheryl D Stimpson
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052,
| | - Nicole Barger
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, CA 95616
| | - Jared P Taglialatela
- Department of Ecology, Evolution and Organismal Biology, Kennesaw State University, Kennesaw, GA 30144
| | | | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - William D Hopkins
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, and Department of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322
| | - Chet C Sherwood
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052
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Hanson KL, Hrvoj-Mihic B, Semendeferi K. A dual comparative approach: integrating lines of evidence from human evolutionary neuroanatomy and neurodevelopmental disorders. BRAIN, BEHAVIOR AND EVOLUTION 2014; 84:135-55. [PMID: 25247986 DOI: 10.1159/000365409] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The evolution of the human brain has been marked by a nearly 3-fold increase in size since our divergence from the last common ancestor shared with chimpanzees and bonobos. Despite increased interest in comparative neuroanatomy and phylogenetic methods, relatively little is known regarding the effects that this enlargement has had on its internal organization, and how certain areas of the brain have differentially expanded over evolutionary time. Analyses of the microstructure of several regions of the human cortex and subcortical structures have demonstrated subtle changes at the cellular and molecular level, suggesting that the human brain is more than simply a 'scaled-up' primate brain. Ongoing research in comparative neuroanatomy has much to offer regarding our understanding of human brain evolution. Through analysis of the neuroanatomical phenotype at the level of reorganization in cytoarchitecture and cellular morphology, new data continue to highlight changes in cell density and organization associated with volumetric changes in discrete regions. An understanding of the functional significance of variation in neural circuitry can further be approached through studies of atypical human development. Many neurodevelopmental disorders cause disruption in systems associated with uniquely human features of cognition, including language and social cognition. Understanding the genetic and developmental mechanisms that underlie variation in the human cognitive phenotype can help to clarify the functional significance of interspecific variation. By uniting approaches from comparative neuroanatomy and neuropathology, insights can be gained that clarify trends in human evolution. Here, we explore these lines of evidence and their significance for understanding functional variation between species as well as within neuropathological variation in the human brain.
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Affiliation(s)
- Kari L Hanson
- Department of Anthropology, University of California, San Diego, La Jolla, Calif., USA
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Barger N, Hanson KL, Teffer K, Schenker-Ahmed NM, Semendeferi K. Evidence for evolutionary specialization in human limbic structures. Front Hum Neurosci 2014; 8:277. [PMID: 24904348 PMCID: PMC4033018 DOI: 10.3389/fnhum.2014.00277] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 04/14/2014] [Indexed: 11/25/2022] Open
Abstract
Increasingly, functional and evolutionary research has highlighted the important contribution emotion processing makes to complex human social cognition. As such, it may be asked whether neural structures involved in emotion processing, commonly referred to as limbic structures, have been impacted in human brain evolution. To address this question, we performed an extensive evolutionary analysis of multiple limbic structures using modern phylogenetic tools. For this analysis, we combined new volumetric data for the hominoid (human and ape) amygdala and 4 amygdaloid nuclei, hippocampus, and striatum, collected using stereological methods in complete histological series, with previously published datasets on the amygdala, orbital and medial frontal cortex, and insula, as well as a non-limbic structure, the dorsal frontal cortex, for contrast. We performed a parallel analysis using large published datasets including many anthropoid species (human, ape, and monkey), but fewer hominoids, for the amygdala and 2 amygdaloid subdivisions, hippocampus, schizocortex, striatum, and septal nuclei. To address evolutionary change, we compared observed human values to values predicted from regressions run through (a) non-human hominoids and (b) non-human anthropoids, assessing phylogenetic influence using phylogenetic generalized least squares regression. Compared with other hominoids, the volumes of the hippocampus, the lateral nucleus of the amygdala, and the orbital frontal cortex were, respectively, 50, 37, and 11% greater in humans than predicted for an ape of human hemisphere volume, while the medial and dorsal frontal cortex were, respectively, 26 and 29% significantly smaller. Compared with other anthropoids, only human values for the striatum fell significantly below predicted values. Overall, the data present support for the idea that regions involved in emotion processing are not necessarily conserved or regressive, but may even be enhanced in recent human evolution.
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Affiliation(s)
- Nicole Barger
- Department of Anthropology, University of California San Diego La Jolla, CA, USA ; Psychiatry and Behavioral Sciences, MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis Sacramento, CA, USA
| | - Kari L Hanson
- Department of Anthropology, University of California San Diego La Jolla, CA, USA
| | - Kate Teffer
- Department of Anthropology, University of California San Diego La Jolla, CA, USA
| | | | - Katerina Semendeferi
- Department of Anthropology, University of California San Diego La Jolla, CA, USA ; Neuroscience Graduate Program, University of California San Diego La Jolla, CA, USA
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Shukla R, Watakabe A, Yamamori T. mRNA expression profile of serotonin receptor subtypes and distribution of serotonergic terminations in marmoset brain. Front Neural Circuits 2014; 8:52. [PMID: 24904298 PMCID: PMC4032978 DOI: 10.3389/fncir.2014.00052] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 04/25/2014] [Indexed: 01/06/2023] Open
Abstract
To better understand serotonin function in the primate brain, we examined the mRNA expression patterns of all the 13 members of the serotonin receptor (5HTR) family, by in situ hybridization (ISH) and the distribution of serotonergic terminations by serotonin transporter (SERT) protein immunohistochemical analysis. Ten of the 13 5HTRs showed significant mRNA expressions in the marmoset brain. Our study shows several new features of the organization of serotonergic systems in the marmoset brain. (1) The thalamus expressed only a limited number of receptor subtypes compared with the cortex, hippocampus, and other subcortical regions. (2) In the cortex, there are layer-selective and area-selective mRNA expressions of 5HTRs. (3) Highly localized mRNA expressions of 5HT1F and 5HT3A were observed. (4) There was a conspicuous overlap of the mRNA expressions of receptor subtypes known to have somatodendritic localization of receptor proteins with dense serotonergic terminations in the visual cortex, the central lateral (CL) nucleus of the thalamus, the presubiculum, and the medial mammillary nucleus of the hypothalamus. This suggests a high correlation between serotonin availability and receptor expression at these locations. (5) The 5HTRs show differences in mRNA expression pattern between the marmoset and mouse cortices whereas the patterns of both the species were much similar in the hippocampus. We discuss the possible roles of 5HTRs in the marmoset brain revealed by the analysis of their overall mRNA expression patterns.
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Affiliation(s)
- Rammohan Shukla
- Division of Brain Biology, National Institute for Basic Biology Okazaki, Japan ; Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI) Okazaki, Japan
| | - Akiya Watakabe
- Division of Brain Biology, National Institute for Basic Biology Okazaki, Japan ; Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI) Okazaki, Japan
| | - Tetsuo Yamamori
- Division of Brain Biology, National Institute for Basic Biology Okazaki, Japan ; Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI) Okazaki, Japan
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Abstract
The basal forebrain cholinergic system modulates neuronal excitability and vascular tone throughout the cerebral cortex and hippocampus. This system is severely affected in Alzheimer's disease (AD), and drug treatment to enhance cholinergic signaling is widely used as symptomatic therapy in AD. Defining the full morphologies of individual basal forebrain cholinergic neurons has, until now, been technically beyond reach due to their large axon arbor sizes. Using genetically-directed sparse labeling, we have characterized the complete morphologies of basal forebrain cholinergic neurons in the mouse. Individual arbors were observed to span multiple cortical columns, and to have >1000 branch points and total axon lengths up to 50 cm. In an AD model, cholinergic axons were slowly lost and there was an accumulation of axon-derived material in discrete puncta. Calculations based on published morphometric data indicate that basal forebrain cholinergic neurons in humans have a mean axon length of ∼100 meters. DOI:http://dx.doi.org/10.7554/eLife.02444.001 The human brain is made up of roughly 80 to 100 billion neurons, organized into extensive networks. Each neuron consists of a number of components: a cell body, which contains the nucleus; numerous short protrusions from the cell body called dendrites; and a long thin structure called an axon that carries the electrical signals generated in the cell body and the dendrites to the next neuron in the network. One of the most studied networks in the human brain is the basal forebrain network, which is made up of large neurons that communicate with one another using a chemical transmitter called acetylcholine. This network has a key role in cognition, and its neurons are among the first to degenerate in Alzheimer's disease. However, relatively little is known about the structure of these ‘cholinergic’ neurons because their large size makes them difficult to study using standard techniques. Now, Wu et al. have visualized, for the first time, the complete 3D structure of cholinergic neurons in the mouse forebrain. The mice in question had been genetically modified so that only ten or so of their many thousands of cholinergic neurons expressed a distinctive ‘marker’ protein. This made it possible to distinguish these neurons from surrounding brain tissue in order to visualize their structures. The resulting pictures clearly illustrate the neurons' complexity, with individual axons in adult mice displaying up to 1000 branches. Measurements showed that each cholinergic axon in the mouse brain is roughly 30 centimeters long, even though the brain itself is less than 2 centimeters from front to back. Based on measurements by other researchers, Wu et al. calculated that the axons of single cholinergic neurons in the human brain are about 100 meters long on average. The extreme length and complex branching structure of cholinergic forebrain neurons helps to explain why each neuron is able to modulate the activity of many others in the network. It could also explain their vulnerability to degeneration, as the need to transport materials over such long distances may limit the ability of these neurons to respond to damage. DOI:http://dx.doi.org/10.7554/eLife.02444.002
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Affiliation(s)
- Hao Wu
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - John Williams
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Jeremy Nathans
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States Department of Opthalmology, Johns Hopkins University School of Medicine, Baltimore, United States
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Raghanti MA, Edler MK, Meindl RS, Sudduth J, Bohush T, Erwin JM, Stimpson CD, Hof PR, Sherwood CC. Humans and great apes share increased neocortical neuropeptide Y innervation compared to other haplorhine primates. Front Hum Neurosci 2014; 8:101. [PMID: 24616688 PMCID: PMC3937817 DOI: 10.3389/fnhum.2014.00101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/10/2014] [Indexed: 11/24/2022] Open
Abstract
Neuropeptide Y (NPY) plays a role in a variety of basic physiological functions and has also been implicated in regulating cognition, including learning and memory. A decrease in neocortical NPY has been reported for Alzheimer's disease, schizophrenia, bipolar disorder, and depression, potentially contributing to associated cognitive deficits. The goal of the present analysis was to examine variation in neocortical NPY-immunoreactive axon and varicosity density among haplorhine primates (monkeys, apes, and humans). Stereologic methods were used to measure the ratios of NPY-expressing axon length density to total neuron density (ALv/Nv) and NPY-immunoreactive varicosity density to neuron density (Vv/Nv), as well as the mean varicosity spacing in neocortical areas 10, 24, 44, and 22 (Tpt) of humans, African great apes, New World monkeys, and Old World monkeys. Humans and great apes showed increased cortical NPY innervation relative to monkey species for ALv/Nv and Vv/Nv. Furthermore, humans and great apes displayed a conserved pattern of varicosity spacing across cortical areas and layers, with no differences between cortical layers or among cortical areas. These phylogenetic differences may be related to shared life history variables and may reflect specific cognitive abilities.
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Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology, School of Biomedical Sciences, Kent State UniversityKent, OH, USA
| | - Melissa K. Edler
- Department of Anthropology, School of Biomedical Sciences, Kent State UniversityKent, OH, USA
| | - Richard S. Meindl
- Department of Anthropology, School of Biomedical Sciences, Kent State UniversityKent, OH, USA
| | - Jessica Sudduth
- Department of Anthropology, School of Biomedical Sciences, Kent State UniversityKent, OH, USA
| | - Tatiana Bohush
- Department of Anthropology, School of Biomedical Sciences, Kent State UniversityKent, OH, USA
| | - Joseph M. Erwin
- Department of Anthropology, The George Washington UniversityWashington, DC, USA
| | - Cheryl D. Stimpson
- Department of Anthropology, The George Washington UniversityWashington, DC, USA
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount SinaiNew York, NY, USA
- New York Consortium in Evolutionary PrimatologyNew York, NY, USA
| | - Chet C. Sherwood
- Department of Anthropology, The George Washington UniversityWashington, DC, USA
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Rahm C, Liberg B, Kristoffersen-Wiberg M, Aspelin P, Msghina M. Differential Effects of Single-Dose Escitalopram on Cognitive and Affective Interference during Stroop Task. Front Psychiatry 2014; 5:21. [PMID: 24616708 PMCID: PMC3934307 DOI: 10.3389/fpsyt.2014.00021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 02/10/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Our aim was to study the regulatory role of serotonin [(5-hydroxytryptamine (5-HT)] on two key nodes in the cognitive control networks - the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC). We hypothesized that increasing the levels of 5-HT would preferentially modulate the activity in ACC during cognitive control during interference by negative affects compared to cognitive control during interference by a superimposed cognitive task. METHODS We performed a functional magnetic resonance imaging investigation on 11 healthy individuals, comparing the effects of the selective 5-HT reuptake inhibitor escitalopram on brain oxygenation level dependent signals in the ACC and the DLPFC using affective and cognitive counting Stroop paradigms (aStroop and cStroop). RESULTS Escitalopram significantly decreased the activity in rostral ACC during aStroop compared to cStroop (p < 0.05). In the absence of escitalopram, both aStroop and cStroop significantly activated ACC and DLPFC (Z ≥ 2.3, p < 0.05). CONCLUSION We conclude that escitalopram in a region and task specific manner modified the cognitive control networks and preferentially decreased activity induced by affective interference in the ACC.
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Affiliation(s)
- Christoffer Rahm
- Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden
| | - Benny Liberg
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet , Stockholm , Sweden
| | | | - Peter Aspelin
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet , Stockholm , Sweden
| | - Mussie Msghina
- Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden
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31
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Zikopoulos B, Barbas H. Altered neural connectivity in excitatory and inhibitory cortical circuits in autism. Front Hum Neurosci 2013; 7:609. [PMID: 24098278 PMCID: PMC3784686 DOI: 10.3389/fnhum.2013.00609] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 09/06/2013] [Indexed: 12/12/2022] Open
Abstract
Converging evidence from diverse studies suggests that atypical brain connectivity in autism affects in distinct ways short- and long-range cortical pathways, disrupting neural communication and the balance of excitation and inhibition. This hypothesis is based mostly on functional non-invasive studies that show atypical synchronization and connectivity patterns between cortical areas in children and adults with autism. Indirect methods to study the course and integrity of major brain pathways at low resolution show changes in fractional anisotropy (FA) or diffusivity of the white matter in autism. Findings in post-mortem brains of adults with autism provide evidence of changes in the fine structure of axons below prefrontal cortices, which communicate over short- or long-range pathways with other cortices and subcortical structures. Here we focus on evidence of cellular and axon features that likely underlie the changes in short- and long-range communication in autism. We review recent findings of changes in the shape, thickness, and volume of brain areas, cytoarchitecture, neuronal morphology, cellular elements, and structural and neurochemical features of individual axons in the white matter, where pathology is evident even in gross images. We relate cellular and molecular features to imaging and genetic studies that highlight a variety of polymorphisms and epigenetic factors that primarily affect neurite growth and synapse formation and function in autism. We report preliminary findings of changes in autism in the ratio of distinct types of inhibitory neurons in prefrontal cortex, known to shape network dynamics and the balance of excitation and inhibition. Finally we present a model that synthesizes diverse findings by relating them to developmental events, with a goal to identify common processes that perturb development in autism and affect neural communication, reflected in altered patterns of attention, social interactions, and language.
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Affiliation(s)
- Basilis Zikopoulos
- Neural Systems Laboratory, Department of Health Sciences, Boston University Boston, MA, USA
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32
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Fluoxetine (prozac) and serotonin act on excitatory synaptic transmission to suppress single layer 2/3 pyramidal neuron-triggered cell assemblies in the human prefrontal cortex. J Neurosci 2013; 32:16369-78. [PMID: 23152619 DOI: 10.1523/jneurosci.2618-12.2012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Selective serotonin reuptake inhibitors are the most widely prescribed drugs targeting the CNS with acute and chronic effects in cognitive, emotional and behavioral processes. This suggests that microcircuits of the human cerebral cortex are powerfully modulated by selective serotonin reuptake inhibitors, however, direct measurements of serotonergic regulation on human synaptic interactions are missing. Using multiple whole-cell patch-clamp recordings from neurons in acute cortical slices derived from nonpathological human samples of the prefrontal cortex, we show that neuronal assemblies triggered by single action potentials of individual neurons in the human cortex are suppressed by therapeutic doses of fluoxetine (Prozac). This effect is boosted and can be mimicked by physiological concentrations of serotonin through 5HT-2A and 5HT-1A receptors. Monosynaptic excitatory connections from pyramidal cells to interneurons were suppressed by application of serotonin leaving the monosynaptic output of GABAergic cells unaffected. Changes in failure rate, in paired-pulse ratio, and in the coefficient of variation of the amplitude of EPSPs suggest a presynaptic action of serotonin. In conclusion, activation of neuronal assemblies, which were suggested as building blocks of high order cognitive processes, are effectively downregulated by the acute action of selective serotonin reuptake inhibitors or serotonin at the site of pyramidal output in human microcircuits.
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Linley SB, Hoover WB, Vertes RP. Pattern of distribution of serotonergic fibers to the orbitomedial and insular cortex in the rat. J Chem Neuroanat 2013; 48-49:29-45. [PMID: 23337940 DOI: 10.1016/j.jchemneu.2012.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 12/13/2012] [Accepted: 12/14/2012] [Indexed: 01/23/2023]
Abstract
As is well recognized, serotonergic (5-HT) fibers distribute widely throughout the brain, including the cerebral cortex. Although some early reports described the 5-HT innervation of the prefrontal cortex (PFC) in rats, the focus was on sensorimotor regions and not on the 'limbic' PFC - or on the medial, orbital and insular cortices. In addition, no reports have described the distribution of 5-HT fibers to PFC in rats using antisera to the serotonin transporter (SERT). Using immunostaining for SERT, we examined the pattern of distribution of 5-HT fibers to the medial, orbital and insular cortices in the rat. We show that 5-HT fibers distribute massively throughout all divisions of the PFC, with distinct laminar variations. Specifically, 5-HT fibers were densely concentrated in superficial (layer 1) and deep (layers 5/6) of the PFC but less heavily so in intermediate layers (layers 2/3). This pattern was most pronounced in the orbital cortex, particularly in the ventral and ventrolateral orbital cortices. With the emergence of granular divisions of the insular cortex, the granular cell layer (layer 4) was readily identifiable by a dense band of labeling confined to it, separating layer 4 from less heavily labeled superficial and deep layers. The pattern of 5-HT innervation of medial, orbital and insular cortices significantly differed from that of sensorimotor regions of the PFC. Serotonergic labeling was much denser overall in limbic compared to non-limbic regions of the PFC, as was striking demonstrated by the generally weaker labeling in layers 1-3 of the primary sensory and motor cortices. The massive serotonergic innervation of the medial, orbital and insular divisions of the PFC likely contributes substantially to well established serotonergic effects on affective and cognitive functions, including a key role in many neurological and psychiatric diseases.
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Affiliation(s)
- Stephanie B Linley
- Department of Psychology, Florida Atlantic University, Boca Raton, FL 33431, United States
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Spocter MA, Hopkins WD, Barks SK, Bianchi S, Hehmeyer AE, Anderson SM, Stimpson CD, Fobbs AJ, Hof PR, Sherwood CC. Neuropil distribution in the cerebral cortex differs between humans and chimpanzees. J Comp Neurol 2012; 520:2917-29. [PMID: 22350926 DOI: 10.1002/cne.23074] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Increased connectivity of high-order association regions in the neocortex has been proposed as a defining feature of human brain evolution. At present, however, there are limited comparative data to examine this claim fully. We tested the hypothesis that the distribution of neuropil across areas of the neocortex of humans differs from that of one of our closest living relatives, the common chimpanzee. The neuropil provides a proxy measure of total connectivity within a local region because it is composed mostly of dendrites, axons, and synapses. Using image analysis techniques, we quantified the neuropil fraction from both hemispheres in six cytoarchitectonically defined regions including frontopolar cortex (area 10), Broca's area (area 45), frontoinsular cortex (area FI), primary motor cortex (area 4), primary auditory cortex (area 41/42), and the planum temporale (area 22). Our results demonstrate that humans exhibit a unique distribution of neuropil in the neocortex compared to chimpanzees. In particular, the human frontopolar cortex and the frontoinsular cortex had a significantly higher neuropil fraction than the other areas. In chimpanzees these prefrontal regions did not display significantly more neuropil, but the primary auditory cortex had a lower neuropil fraction than other areas. Our results support the conclusion that enhanced connectivity in the prefrontal cortex accompanied the evolution of the human brain. These species differences in neuropil distribution may offer insight into the neural basis of human cognition, reflecting enhancement of the integrative capacity of the prefrontal cortex.
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Affiliation(s)
- Muhammad A Spocter
- Department of Anthropology, The George Washington University, Washington, DC 20052, USA
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Sayers K, Raghanti MA, Lovejoy CO. Human Evolution and the Chimpanzee Referential Doctrine. ANNUAL REVIEW OF ANTHROPOLOGY 2012. [DOI: 10.1146/annurev-anthro-092611-145815] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chimpanzees are our closest living genomic relatives, but they lack the bipedal locomotion, markedly enlarged brains, and advanced communication skills of humans. This has led many to view them as “primitive” and to presume that their behavior and anatomy are also primitive. If true, they could serve as models of our last common ancestor (LCA), i.e., a territorially aggressive knuckle walker, reliant on vertical climbing and below-branch suspension to access the high canopy as a ripe-fruit frugivore. Ardipithecus now provides abundant information that the LCA differed substantially from chimpanzees (as well as bonobos and gorillas), both anatomically and behaviorally, and exhibited many characters that are more similar to those of modern humans than to any living ape. This major extension of the hominoid fossil record contravenes strict referential modeling based on the extant chimpanzee and greatly improves our ability to reconstruct the LCA more accurately, but only when viewed within the broader context of evolutionary ecology.
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Affiliation(s)
- Ken Sayers
- Language Research Center, Georgia State University, Decatur, Georgia 30034
| | - Mary Ann Raghanti
- Department of Anthropology and Division of Biomedical Sciences, Kent State University, Kent, Ohio 44242;,
| | - C. Owen Lovejoy
- Department of Anthropology and Division of Biomedical Sciences, Kent State University, Kent, Ohio 44242;,
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Raghanti MA, Conley T, Sudduth J, Erwin JM, Stimpson CD, Hof PR, Sherwood CC. Neuropeptide Y-immunoreactive neurons in the cerebral cortex of humans and other haplorrhine primates. Am J Primatol 2012; 75:415-24. [PMID: 23042407 DOI: 10.1002/ajp.22082] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 08/13/2012] [Accepted: 08/14/2012] [Indexed: 11/09/2022]
Abstract
We examined the distribution of neurons immunoreactive for neuropeptide Y (NPY) in the posterior part of the superior temporal cortex (Brodmann's area 22 or area Tpt) of humans and nonhuman haplorrhine primates. NPY has been implicated in learning and memory and the density of NPY-expressing cortical neurons and axons is reduced in depression, bipolar disorder, schizophrenia, and Alzheimer's disease. Due to the role that NPY plays in both cognition and neurodegenerative diseases, we tested the hypothesis that the density of cortical and interstitial neurons expressing NPY was increased in humans relative to other primate species. The study sample included great apes (chimpanzee and gorilla), Old World monkeys (pigtailed macaque, moor macaque, and baboon) and New World monkeys (squirrel monkey and capuchin). Stereologic methods were used to estimate the density of NPY-immunoreactive (-ir) neurons in layers I-VI of area Tpt and the subjacent white matter. Adjacent Nissl-stained sections were used to calculate local densities of all neurons. The ratio of NPY-ir neurons to total neurons within area Tpt and the total density of NPY-ir neurons within the white matter were compared among species. Overall, NPY-ir neurons represented only an average of 0.006% of the total neuron population. While there were significant differences among species, phylogenetic trends in NPY-ir neuron distributions were not observed and humans did not differ from other primates. However, variation among species warrants further investigation into the distribution of this neuromodulator system.
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Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA.
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Mesulam M. The evolving landscape of human cortical connectivity: facts and inferences. Neuroimage 2012; 62:2182-9. [PMID: 22209814 PMCID: PMC3321392 DOI: 10.1016/j.neuroimage.2011.12.033] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 11/11/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022] Open
Abstract
Human cognitive brain mapping is at a crossroads. On the one hand, it can access a rich data set of synaptic connectivity in the cerebral cortex of the monkey, an animal that lacks many of the complicated behaviors of interest. On the other hand, it is rapidly amassing an even richer data set on the functional map of the human cerebral cortex, but with relatively little hard data on underlying structural connectivity. This second point tends to be blurred in the current literature because of the multiple ways in which the term 'connection' is used in the context of the human brain. In some instances the term is used at a conceptual level, to designate a pathway that should be there if the behavior is to be performed. In other instances, it refers to the computational demonstration of a functional relationship, the structural basis of which is not necessarily known. A third usage is based on connections that are known to exist in the monkey and that are inferred to also exist in the human. The fourth and most direct usage involves connections structurally proven to exist in the human. These four usages have been invoked interchangeably to propose connectivistic mechanisms of human cognitive function. To enlarge the currently limited data set on structural connectivity is of considerable importance for conducting biologically more valid explorations of large-scale neurocognitive networks. This challenging goal will require histological laboratory investigations of the human brain to resume their former prominence and to play an increasingly more substantial role in brain mapping research.
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Sherwood CC, Bauernfeind AL, Bianchi S, Raghanti MA, Hof PR. Human brain evolution writ large and small. PROGRESS IN BRAIN RESEARCH 2012; 195:237-54. [PMID: 22230630 DOI: 10.1016/b978-0-444-53860-4.00011-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human evolution was marked by an extraordinary increase in total brain size relative to body size. While it is certain that increased encephalization is an important factor contributing to the origin of our species-specific cognitive abilities, it is difficult to disentangle which aspects of human neural structure and function are correlated by-products of brain size expansion from those that are specifically related to particular psychological specializations, such as language and enhanced "mentalizing" abilities. In this chapter, we review evidence from allometric scaling studies demonstrating that much of human neocortical organization can be understood as a product of brain enlargement. Defining extra-allometric specializations in humans is often hampered by a severe lack of comparative data from the same neuroanatomical variables across a broad range of primates. When possible, we highlight evidence for features of human neocortical architecture and function that cannot be easily explained as correlates of brain size and, hence, might be more directly associated with the evolution of uniquely human cognitive capacities.
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Affiliation(s)
- Chet C Sherwood
- Department of Anthropology, The George Washington University, Washington, DC, USA.
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Lewitus E, Hof PR, Sherwood CC. Phylogenetic comparison of neuron and glia densities in the primary visual cortex and hippocampus of carnivores and primates. Evolution 2012; 66:2551-63. [PMID: 22834752 DOI: 10.1111/j.1558-5646.2012.01601.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A major focus of comparative neuroanatomy has been on whether the mammalian brain evolves in a concerted or a mosaic fashion. Workers have examined variation in the volume of different brain regions across taxa to test the degree to which selection is constrained by the timing of events in neural development. Whether a conserved neurogenetic program in the mammalian brain constrains the distribution of different cell types, however, has not yet been investigated. Here we tested for evidence of evolutionary constraints on the densities of different cell types in the primary visual cortex (V1) and the hippocampus in 37 primate and 21 carnivore species. Cellular densities in V1 and the hippocampus scale isometrically with respect to one another in carnivores, as predicted by the concerted evolution hypothesis. In primates, however, cellular distributions in the hippocampus and primary visual cortex show no correlations, which supports the hypothesis of mosaic brain evolution. We therefore provide evidence for the presence of constraints controlling the adult densities of different cell types in disparate regions of the mammalian brain, but also for specializations along the primate lineage. We propose that adaptations to modularity at the cellular level may carry a deep phylogenetic signal.
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Affiliation(s)
- Eric Lewitus
- Department of Anthropology, University College London, London WC1H 0BW, United Kingdom.
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Bufill E, Agustí J, Blesa R. Human neoteny revisited: The case of synaptic plasticity. Am J Hum Biol 2011; 23:729-39. [PMID: 21957070 DOI: 10.1002/ajhb.21225] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 08/29/2011] [Accepted: 09/06/2011] [Indexed: 01/12/2023] Open
Abstract
The process of learning requires morphological changes in the neuronal connections and the formation of new synapses. Due to the importance of memory and learning in our species, it has been suggested that the synaptic plasticity in a number of association areas is higher in the human brain than in other primates. Cortical neurons in mammals are characterized by higher metabolism, activity, and synaptic plasticity during development and the juvenile stage than in the adult. In Homo sapiens, brain development is retarded compared with other primates, especially in some association areas. These areas are characterized by the presence of neurons, which remain structurally immature throughout their lifespans and show an increase in the expression of the genes, which deal with metabolism and the activity and synaptic plasticity in adulthood. The retention of juvenile features in some adult neurons in our species has occurred in areas, which are related to episodic memory, planning, and social navigation. The increase of the aerobic metabolism in these neurons may lead, however, to higher levels of oxidative stress, therefore, favoring the development of neurodegenerative diseases which are exclusive, or almost exclusive, to humans, such as Alzheimer's disease.
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Affiliation(s)
- Enric Bufill
- Servei de Neurología, Consorci Hospitalari de Vic, Spain.
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Abstract
The past two decades have witnessed tremendous advances in noninvasive and postmortem neuroscientific techniques, advances that have made it possible, for the first time, to compare in detail the organization of the human brain to that of other primates. Studies comparing humans to chimpanzees and other great apes reveal that human brain evolution was not merely a matter of enlargement, but involved changes at all levels of organization that have been examined. These include the cellular and laminar organization of cortical areas; the higher order organization of the cortex, as reflected in the expansion of association cortex (in absolute terms, as well as relative to primary areas); the distribution of long-distance cortical connections; and hemispheric asymmetry. Additionally, genetic differences between humans and other primates have proven to be more extensive than previously thought, raising the possibility that human brain evolution involved significant modifications of neurophysiology and cerebral energy metabolism.
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Affiliation(s)
- Todd M Preuss
- Division of Neuropathology and Neurodegenerative Diseases and Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA.
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Eaton JL, Roache L, Nguyen KN, Cushing BS, Troyer E, Papademetriou E, Raghanti MA. Organizational effects of oxytocin on serotonin innervation. Dev Psychobiol 2011; 54:92-7. [DOI: 10.1002/dev.20566] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/25/2011] [Indexed: 01/08/2023]
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Bhagwandin A, Fuxe K, Bennett NC, Manger PR. Distribution of orexinergic neurons and their terminal networks in the brains of two species of African mole rats. J Chem Neuroanat 2011; 41:32-42. [DOI: 10.1016/j.jchemneu.2010.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 11/01/2010] [Accepted: 11/03/2010] [Indexed: 10/18/2022]
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Sarko DK, Leitch DB, Girard I, Sikes RS, Catania KC. Organization of somatosensory cortex in the Northern grasshopper mouse (Onychomys leucogaster), a predatory rodent. J Comp Neurol 2011; 519:64-74. [PMID: 21120928 PMCID: PMC3064439 DOI: 10.1002/cne.22504] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Northern grasshopper mice (Onychomys leucogaster) are among the most highly carnivorous rodents in North America. Because predatory mammals may have specialization of senses used to detect prey, we investigated the organization of sensory areas within grasshopper mouse neocortex and quantified the number of myelinated axons in grasshopper mouse trigeminal, cochlear, and optic nerves. Multiunit electrophysiological recordings combined with analysis of flattened sections of neocortex processed for cytochrome oxidase were used to determine the topography of primary somatosensory cortex (S1) and the location and size of both the visual and auditory cortex in adult animals. These findings were then related to the distinctive chemoarchitecture of layer IV visible in flattened cortical sections of juvenile grasshopper mice labeled with the serotonin transporter (SERT) antibody, revealing a striking correspondence between electrophysiological maps and cortical anatomy.
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Affiliation(s)
- Diana K Sarko
- Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, Tennessee 37232, USA.
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Semendeferi K, Teffer K, Buxhoeveden DP, Park MS, Bludau S, Amunts K, Travis K, Buckwalter J. Spatial organization of neurons in the frontal pole sets humans apart from great apes. Cereb Cortex 2010; 21:1485-97. [PMID: 21098620 DOI: 10.1093/cercor/bhq191] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Few morphological differences have been identified so far that distinguish the human brain from the brains of our closest relatives, the apes. Comparative analyses of the spatial organization of cortical neurons, including minicolumns, can aid our understanding of the functionally relevant aspects of microcircuitry. We measured horizontal spacing distance and gray-level ratio in layer III of 4 regions of human and ape cortex in all 6 living hominoid species: frontal pole (Brodmann area [BA] 10), and primary motor (BA 4), primary somatosensory (BA 3), and primary visual cortex (BA 17). Our results identified significant differences between humans and apes in the frontal pole (BA 10). Within the human brain, there were also significant differences between the frontal pole and 2 of the 3 regions studied (BA 3 and BA 17). Differences between BA 10 and BA 4 were present but did not reach significance. These findings in combination with earlier findings on BA 44 and BA 45 suggest that human brain evolution was likely characterized by an increase in the number and width of minicolumns and the space available for interconnectivity between neurons in the frontal lobe, especially the prefrontal cortex.
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Affiliation(s)
- Katerina Semendeferi
- Department of Anthropology, University of California, San Diego, La Jolla, CA 92093, USA
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Yokoyama C, Yamanaka H, Onoe K, Kawasaki A, Nagata H, Shirakami K, Doi H, Onoe H. Mapping of serotonin transporters by positron emission tomography with [11c]DASB in conscious common marmosets: Comparison with rhesus monkeys. Synapse 2010; 64:594-601. [DOI: 10.1002/syn.20766] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sherwood CC, Raghanti MA, Stimpson CD, Spocter MA, Uddin M, Boddy AM, Wildman DE, Bonar CJ, Lewandowski AH, Phillips KA, Erwin JM, Hof PR. Inhibitory interneurons of the human prefrontal cortex display conserved evolution of the phenotype and related genes. Proc Biol Sci 2009; 277:1011-20. [PMID: 19955152 DOI: 10.1098/rspb.2009.1831] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Inhibitory interneurons participate in local processing circuits, playing a central role in executive cognitive functions of the prefrontal cortex. Although humans differ from other primates in a number of cognitive domains, it is not currently known whether the interneuron system has changed in the course of primate evolution leading to our species. In this study, we examined the distribution of different interneuron subtypes in the prefrontal cortex of anthropoid primates as revealed by immunohistochemistry against the calcium-binding proteins calbindin, calretinin and parvalbumin. In addition, we tested whether genes involved in the specification, differentiation and migration of interneurons show evidence of positive selection in the evolution of humans. Our findings demonstrate that cellular distributions of interneuron subtypes in human prefrontal cortex are similar to other anthropoid primates and can be explained by general scaling rules. Furthermore, genes underlying interneuron development are highly conserved at the amino acid level in primate evolution. Taken together, these results suggest that the prefrontal cortex in humans retains a similar inhibitory circuitry to that in closely related primates, even though it performs functional operations that are unique to our species. Thus, it is likely that other significant modifications to the connectivity and molecular biology of the prefrontal cortex were overlaid on this conserved interneuron architecture in the course of human evolution.
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Affiliation(s)
- Chet C Sherwood
- Department of Anthropology, The George Washington University, Washington, DC 20052, USA.
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Rilling JK. Neuroscientific approaches and applications within anthropology. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; Suppl 47:2-32. [PMID: 19003891 DOI: 10.1002/ajpa.20947] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Many of the most distinctive attributes of our species are a product of our brains. To understand the function, development, variability, and evolution of the human brain, we must engage with the field of neuroscience. Neuroscientific methods can be used to investigate research topics that are of special interest to anthropologists, such as the neural bases of primate behavioral diversity, human brain evolution, and human brain development. Traditional neuroscience methods had to rely on investigation of postmortem brains, as well as invasive studies in living nonhuman primates. However, recent neuroimaging methods have made it possible to compare living human and nonhuman primate brains using noninvasive techniques such as structural and functional magnetic resonance imaging, positron emission tomography, and diffusion tensor imaging. These methods are providing an integrated picture of brain structure and function that was not previously available. With a combination of these traditional and modern neuroscience methods, we are beginning to explore and understand the neural bases of some of the most distinctive cognitive and behavioral attributes of the human species, including language, tool use, altruism, and mental self-projection, and we can now begin to propose plausible scenarios by which the neural substrates supporting these human specializations evolved from pre-existing neural circuitry serving related functions in common ancestors we shared with the living nonhuman primates. Consideration of the process of neurodevelopment suggests plausible mechanisms by which the highly encephalized human brain might have evolved. Neurodevelopmental studies also demonstrate that experience can shape both brain structure and function, providing a mechanism by which people of different cultures learn to act and think differently. Finally, not only can anthropologists benefit from neuroscience, neuroscience can benefit from the more sophisticated concept of evolution that anthropology offers, including an appreciation of evolutionary diversity as well as consideration of the process by which the human brain was formed during evolution.
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Affiliation(s)
- James K Rilling
- Department of Anthropology, Emory University, Atlanta, GA 30322, USA.
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