51
|
Kumar A, Pareek V, Faiq MA, Ghosh SK, Kumari C. ADULT NEUROGENESIS IN HUMANS: A Review of Basic Concepts, History, Current Research, and Clinical Implications. INNOVATIONS IN CLINICAL NEUROSCIENCE 2019; 16:30-37. [PMID: 31440399 PMCID: PMC6659986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Neurogenesis in adult humans remains a controversial area of research among neuroscientists. Methodological challenges have hampered investigators from conducting high-quality, in-vivo studies that can help elucidate the presence and/or activity of neurogenesis in human brains. Additionally, the studies that have been done in humans report conflicting results, further adding to the ambiguity surrounding the concept of adult neurogenesis in humans. In this review article, the authors seek to help clarify the concept of adult neurogenesis by providing an overview of the basic concept, as we currently understand it, including its historical birth and evolution. The authors also review and discuss current key studies (pro and con) on adult neurogenesis in humans and animals, as well as research challenges with potential solutions. Finally, the authors discuss the clinical implications of adult neurogenesis in humans, based on what we know so far, including its potential use as a drug target in the development of pharmacological treatments for various neuropsychiatric disorders.
Collapse
Affiliation(s)
- Ashutosh Kumar
- Drs. Kumar and Ghosh are with the Department of Anatomy at the All India Institute of Medical Sciences (AIIMS) in Patna, India
- Dr. Pareek is with the Computational Neuroscience and Neuroimaging Division at National Brain Research Centre (NBRC) in Manesar, Haryana, India
- Dr. Faiq is with the Neuroimaging and Visual Science Laboratory at Langone Medical Centre, New York University School of Medicine in New York, New York
- Dr. Kumari is with the Department of Anatomy at Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India
- Drs. Kumar and Faiq are with All India Institute of Medical Sciences (AIIMS) in New Delhi, India
- Drs. Kumar, Pareek, Faiq, Ghosh, and Kumari are with the Etiologically Elusive Disorders Research Network (EEDRN) in New Delhi, India
| | - Vikas Pareek
- Drs. Kumar and Ghosh are with the Department of Anatomy at the All India Institute of Medical Sciences (AIIMS) in Patna, India
- Dr. Pareek is with the Computational Neuroscience and Neuroimaging Division at National Brain Research Centre (NBRC) in Manesar, Haryana, India
- Dr. Faiq is with the Neuroimaging and Visual Science Laboratory at Langone Medical Centre, New York University School of Medicine in New York, New York
- Dr. Kumari is with the Department of Anatomy at Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India
- Drs. Kumar and Faiq are with All India Institute of Medical Sciences (AIIMS) in New Delhi, India
- Drs. Kumar, Pareek, Faiq, Ghosh, and Kumari are with the Etiologically Elusive Disorders Research Network (EEDRN) in New Delhi, India
| | - Muneeb A Faiq
- Drs. Kumar and Ghosh are with the Department of Anatomy at the All India Institute of Medical Sciences (AIIMS) in Patna, India
- Dr. Pareek is with the Computational Neuroscience and Neuroimaging Division at National Brain Research Centre (NBRC) in Manesar, Haryana, India
- Dr. Faiq is with the Neuroimaging and Visual Science Laboratory at Langone Medical Centre, New York University School of Medicine in New York, New York
- Dr. Kumari is with the Department of Anatomy at Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India
- Drs. Kumar and Faiq are with All India Institute of Medical Sciences (AIIMS) in New Delhi, India
- Drs. Kumar, Pareek, Faiq, Ghosh, and Kumari are with the Etiologically Elusive Disorders Research Network (EEDRN) in New Delhi, India
| | - Sanjib K Ghosh
- Drs. Kumar and Ghosh are with the Department of Anatomy at the All India Institute of Medical Sciences (AIIMS) in Patna, India
- Dr. Pareek is with the Computational Neuroscience and Neuroimaging Division at National Brain Research Centre (NBRC) in Manesar, Haryana, India
- Dr. Faiq is with the Neuroimaging and Visual Science Laboratory at Langone Medical Centre, New York University School of Medicine in New York, New York
- Dr. Kumari is with the Department of Anatomy at Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India
- Drs. Kumar and Faiq are with All India Institute of Medical Sciences (AIIMS) in New Delhi, India
- Drs. Kumar, Pareek, Faiq, Ghosh, and Kumari are with the Etiologically Elusive Disorders Research Network (EEDRN) in New Delhi, India
| | - Chiman Kumari
- Drs. Kumar and Ghosh are with the Department of Anatomy at the All India Institute of Medical Sciences (AIIMS) in Patna, India
- Dr. Pareek is with the Computational Neuroscience and Neuroimaging Division at National Brain Research Centre (NBRC) in Manesar, Haryana, India
- Dr. Faiq is with the Neuroimaging and Visual Science Laboratory at Langone Medical Centre, New York University School of Medicine in New York, New York
- Dr. Kumari is with the Department of Anatomy at Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India
- Drs. Kumar and Faiq are with All India Institute of Medical Sciences (AIIMS) in New Delhi, India
- Drs. Kumar, Pareek, Faiq, Ghosh, and Kumari are with the Etiologically Elusive Disorders Research Network (EEDRN) in New Delhi, India
| |
Collapse
|
52
|
Oppenheim RW. Adult Hippocampal Neurogenesis in Mammals (and Humans): The Death of a Central Dogma in Neuroscience and its Replacement by a New Dogma. Dev Neurobiol 2019; 79:268-280. [DOI: 10.1002/dneu.22674] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/12/2019] [Accepted: 03/12/2019] [Indexed: 01/31/2023]
Affiliation(s)
- Ronald W. Oppenheim
- Department of Neurobiology and Anatomy, The Neuroscience Program Wake Forest School of Medicine Medical Center Blvd. Winston‐Salem NC 27157‐1010
| |
Collapse
|
53
|
Watson C, Binks D. Elongation of the CA1 field of the septal hippocampus in ungulates. J Comp Neurol 2019; 527:818-832. [PMID: 30393922 DOI: 10.1002/cne.24573] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 11/06/2022]
Abstract
It is widely assumed that the hippocampal formation seen in laboratory rodents and in primates is typical of that seen in other mammals. We have tested this assumption by examining sections of brains of 56 mammals from 20 mammalian orders from images on the brainmuseum.org website. We found wide variation in the form of the hippocampal formation, the most extreme examples of which are seen in ungulates, which possess an unusual elongation of the distal CA1 of the septal hippocampus. This phenomenon has not previously been reported. In individual coronal sections of the brains of seven artiodactyl ungulates, the pyramidal layer of CA1 is four times as long as CA2 + CA3. In a perissodactyl ungulate (Burchell's zebra) the distal end of CA1 is so large that it forms a number of folds. A similar but less pronounced CA1 elongation was seen in the brains of 14 carnivores. A modest elongation of CA1 is also present in some other placental mammals, notably the elephant shrew, hyrax, capybara, beaver, and rabbit. The elongation was not present in brains of primates, marsupials, or monotremes. The distal part of CA1 has been shown to play a role in object integration into the spatial map. We hypothesize that the distal CA1 enlargement could serve to enhance the ability to integrate objects into spatial navigation, which would be an advantage for migrating herds of ungulates. We suggest that the remarkable elongation of Q5 CA1 represents a major evolutionary specialization in the ungulates.
Collapse
Affiliation(s)
- Charles Watson
- School of Biological Sciences, The University of Western Australia, Perth, Australia.,Neuroscience Research Australia, Sydney, Australia
| | - Daniel Binks
- School of Biological Sciences, The University of Western Australia, Perth, Australia.,Perron Institute of Neurological and Translational Science
| |
Collapse
|
54
|
Augusto-Oliveira M, Arrifano GPF, Malva JO, Crespo-Lopez ME. Adult Hippocampal Neurogenesis in Different Taxonomic Groups: Possible Functional Similarities and Striking Controversies. Cells 2019; 8:cells8020125. [PMID: 30764477 PMCID: PMC6406791 DOI: 10.3390/cells8020125] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/31/2019] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Adult neurogenesis occurs in many species, from fish to mammals, with an apparent reduction in the number of both neurogenic zones and new neurons inserted into established circuits with increasing brain complexity. Although the absolute number of new neurons is high in some species, the ratio of these cells to those already existing in the circuit is low. Continuous replacement/addition plays a role in spatial navigation (migration) and other cognitive processes in birds and rodents, but none of the literature relates adult neurogenesis to spatial navigation and memory in primates and humans. Some models developed by computational neuroscience attribute a high weight to hippocampal adult neurogenesis in learning and memory processes, with greater relevance to pattern separation. In contrast to theories involving neurogenesis in cognitive processes, absence/rarity of neurogenesis in the hippocampus of primates and adult humans was recently suggested and is under intense debate. Although the learning process is supported by plasticity, the retention of memories requires a certain degree of consolidated circuitry structures, otherwise the consolidation process would be hampered. Here, we compare and discuss hippocampal adult neurogenesis in different species and the inherent paradoxical aspects.
Collapse
Affiliation(s)
- Marcus Augusto-Oliveira
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, Brazil.
- Laboratory of Research on Neurodegeneration and Infection, University Hospital João de Barros Barreto, Federal University of Pará, Belém 66073-005, Brazil.
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK.
| | - Gabriela P F Arrifano
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, Brazil.
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK.
| | - João O Malva
- Coimbra Institute for Clinical and Biomedical Research (iCBR), and Center for Neuroscience and Cell Biology and Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, Coimbra 3000-548, Portugal.
| | - Maria Elena Crespo-Lopez
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, Brazil.
| |
Collapse
|
55
|
Imam A, Bhagwandin A, Ajao MS, Ihunwo AO, Manger PR. The brain of the tree pangolin (Manis tricuspis). IV. The hippocampal formation. J Comp Neurol 2019; 527:2393-2412. [PMID: 30592043 DOI: 10.1002/cne.24620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 01/06/2023]
Abstract
Employing a range of standard and immunohistochemical stains we provide a description of the hippocampal formation in the brain of the tree pangolin. For the most part, the architecture, chemical neuroanatomy, and topological relationships of the component parts of the hippocampal formation of the tree pangolin were consistent with that observed in other mammalian species. Within the hippocampus proper fields CA1, 3, and 4 could be identified with certainty, while CA2 was tentatively identified as a small transitional zone between the CA1 and CA3 fields. Within the dentate gyrus evidence for adult hippocampal neurogenesis at a rate comparable to other mammals was observed. The subicular complex and entorhinal cortex also exhibited divisions typically observed in other mammalian species. In contrast to many other mammals, an architecturally and neurochemically distinct CA4 field was observed, supporting Lorente de Nó's proposed CA4 field, at least in some mammalian species. In addition, up to seven laminae were evident in the dentate gyrus. Calretinin immunostaining revealed the three sublamina of the molecular layer, while immunostaining for vesicular glutamate transporter 2 and neurofilament H indicate that the granule cell layer was composed of two sublamina. The similarities and differences observed in the tree pangolin indicate that the hippocampal formation is an anatomically and neurochemically conserved neural unit in mammalian evolution, but minor changes may relate to specific life history features and habits of species.
Collapse
Affiliation(s)
- Aminu Imam
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Moyosore S Ajao
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| |
Collapse
|
56
|
The role of adult hippocampal neurogenesis in brain health and disease. Mol Psychiatry 2019; 24:67-87. [PMID: 29679070 PMCID: PMC6195869 DOI: 10.1038/s41380-018-0036-2] [Citation(s) in RCA: 385] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/15/2018] [Accepted: 01/31/2018] [Indexed: 12/18/2022]
Abstract
Adult neurogenesis in the dentate gyrus of the hippocampus is highly regulated by a number of environmental and cell-intrinsic factors to adapt to environmental changes. Accumulating evidence suggests that adult-born neurons may play distinct physiological roles in hippocampus-dependent functions, such as memory encoding and mood regulation. In addition, several brain diseases, such as neurological diseases and mood disorders, have deleterious effects on adult hippocampal neurogenesis, and some symptoms of those diseases can be partially explained by the dysregulation of adult hippocampal neurogenesis. Here we review a possible link between the physiological functions of adult-born neurons and their roles in pathological conditions.
Collapse
|
57
|
Fares J, Bou Diab Z, Nabha S, Fares Y. Neurogenesis in the adult hippocampus: history, regulation, and prospective roles. Int J Neurosci 2018; 129:598-611. [PMID: 30433866 DOI: 10.1080/00207454.2018.1545771] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The hippocampus is one of the sites in the mammalian brain that is capable of continuously generating controversy. Adult neurogenesis is a remarkable process, and yet an intensely debatable topic in contemporary neuroscience due to its distinctiveness and conceivable impact on neural activity. The belief that neurogenesis continues through adulthood has provoked remarkable efforts to describe how newborn neurons differentiate and incorporate into the adult brain. It has also encouraged studies that investigate the consequences of inadequate neurogenesis in neuropsychiatric and neurodegenerative diseases and explore the potential role of neural progenitor cells in brain repair. The adult nervous system is not static; it is subjected to morphological and physiological alterations at various levels. This plastic mechanism guarantees that the behavioral regulation of the adult nervous system is adaptable in response to varying environmental stimuli. Three regions of the adult brain, the olfactory bulb, the hypothalamus, and the hippocampal dentate gyrus, contain new-born neurons that exhibit an essential role in the natural functional circuitry of the adult brain. Purpose/Aim: This article explores current advancements in adult hippocampal neurogenesis by presenting its history and evolution and studying its association with neural plasticity. The article also discusses the prospective roles of adult hippocampal neurogenesis and describes the intracellular, extracellular, pathological, and environmental factors involved in its regulation. Abbreviations AHN Adult hippocampal neurogenesis AKT Protein kinase B BMP Bone Morphogenic Protein BrdU Bromodeoxyuridine CNS Central nervous system DG Dentate gyrus DISC1 Disrupted-in-schizophrenia 1 FGF-2 Fibroblast Growth Factor 2 GABA Gamma-aminobutyric acid Mbd1 Methyl-CpG-binding domain protein 1 Mecp2 Methyl-CpG-binding protein 2 mTOR Mammalian target of rapamycin NSCs Neural stem cells OB Olfactory bulb; P21: cyclin-dependent kinase inhibitor 1 RBPj Recombination Signal Binding protein for Immunoglobulin Kappa J Region RMS Rostral migratory Stream SGZ Subgranular zone Shh Sonic hedgehog SOX2 SRY (sex determining region Y)-box 2 SVZ Subventricular zone Wnt3 Wingless-type mouse mammary tumor virus.
Collapse
Affiliation(s)
- Jawad Fares
- a Neuroscience Research Center , Faculty of Medical Sciences , Lebanese University , Beirut , Lebanon.,b Department of Neurological Surgery Feinberg School of Medicine , Northwestern University , Chicago , Illinois , USA
| | - Zeina Bou Diab
- a Neuroscience Research Center , Faculty of Medical Sciences , Lebanese University , Beirut , Lebanon
| | - Sanaa Nabha
- a Neuroscience Research Center , Faculty of Medical Sciences , Lebanese University , Beirut , Lebanon
| | - Youssef Fares
- a Neuroscience Research Center , Faculty of Medical Sciences , Lebanese University , Beirut , Lebanon.,c Department of Neurosurgery Faculty of Medical Sciences , Lebanese University , Beirut , Lebanon
| |
Collapse
|
58
|
Jung MW, Lee H, Jeong Y, Lee JW, Lee I. Remembering rewarding futures: A simulation-selection model of the hippocampus. Hippocampus 2018; 28:913-930. [PMID: 30155938 PMCID: PMC6587829 DOI: 10.1002/hipo.23023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/06/2018] [Accepted: 08/23/2018] [Indexed: 02/06/2023]
Abstract
Despite tremendous progress, the neural circuit dynamics underlying hippocampal mnemonic processing remain poorly understood. We propose a new model for hippocampal function-the simulation-selection model-based on recent experimental findings and neuroecological considerations. Under this model, the mammalian hippocampus evolved to simulate and evaluate arbitrary navigation sequences. Specifically, we suggest that CA3 simulates unexperienced navigation sequences in addition to remembering experienced ones, and CA1 selects from among these CA3-generated sequences, reinforcing those that are likely to maximize reward during offline idling states. High-value sequences reinforced in CA1 may allow flexible navigation toward a potential rewarding location during subsequent navigation. We argue that the simulation-selection functions of the hippocampus have evolved in mammals mostly because of the unique navigational needs of land mammals. Our model may account for why the mammalian hippocampus has evolved not only to remember, but also to imagine episodes, and how this might be implemented in its neural circuits.
Collapse
Affiliation(s)
- Min Whan Jung
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeonSouth Korea
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonSouth Korea
| | - Hyunjung Lee
- Department of AnatomyKyungpook National University School of MedicineDaeguSouth Korea
| | - Yeongseok Jeong
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeonSouth Korea
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonSouth Korea
| | - Jong Won Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeonSouth Korea
| | - Inah Lee
- Department of Brain and Cognitive SciencesSeoul National UniversitySeoulSouth Korea
| |
Collapse
|
59
|
Raghanti MA, Wicinski B, Meierovich R, Warda T, Dickstein DL, Reidenberg JS, Tang CY, George JC, Hans Thewissen JGM, Butti C, Hof PR. A Comparison of the Cortical Structure of the Bowhead Whale (Balaena mysticetus), a Basal Mysticete, with Other Cetaceans. Anat Rec (Hoboken) 2018; 302:745-760. [PMID: 30332717 DOI: 10.1002/ar.23991] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 09/12/2017] [Accepted: 10/16/2017] [Indexed: 12/13/2022]
Abstract
Few studies exist of the bowhead whale brain and virtually nothing is known about its cortical cytoarchitecture or how it compares to other cetaceans. Bowhead whales are one of the least encephalized cetaceans and occupy a basal phylogenetic position among mysticetes. Therefore, the bowhead whale is an important specimen for understanding the evolutionary specializations of cetacean brains. Here, we present an overview of the structure and cytoarchitecture of the bowhead whale cerebral cortex gleaned from Nissl-stained sections and magnetic resonance imaging (MRI) in comparison with other mysticetes and odontocetes. In general, the cytoarchitecture of cetacean cortex is consistent in displaying a thin cortex, a thick, prominent layer I, and absence of a granular layer IV. Cell density, composition, and width of layers III, V, and VI vary among cortical regions, and cetacean cortex is cell-sparse relative to that of terrestrial mammals. Notably, all regions of the bowhead cortex possess high numbers of von Economo neurons and fork neurons, with the highest numbers observed at the apex of gyri. The bowhead whale is also distinctive in having a significantly reduced hippocampus that occupies a space below the corpus callosum within the lateral ventricle. Consistent with other balaenids, bowhead whales possess what appears to be a blunted temporal lobe, which is in contrast to the expansive temporal lobes that characterize most odontocetes. The present report demonstrates that many morphological and cytoarchitectural characteristics are conserved among cetaceans, while other features, such as a reduced temporal lobe, may characterize balaenids among mysticetes. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:745-760, 2019. © 2018 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Bridget Wicinski
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rachel Meierovich
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York.,Convent of the Sacred Heart School, New York, New York
| | - Tahia Warda
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Dara L Dickstein
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York.,Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Cheuk Y Tang
- Department of Radiology and Translational Medicine Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - John C George
- Department of Wildlife Management, North Slope Borough, Barrow, Alaska
| | - J G M Hans Thewissen
- Department of Anatomy and Neurobiology, Northeastern Ohio Medical University, Rootstown, Ohio
| | - Camilla Butti
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
60
|
La Rosa C, Bonfanti L. Brain Plasticity in Mammals: An Example for the Role of Comparative Medicine in the Neurosciences. Front Vet Sci 2018; 5:274. [PMID: 30443551 PMCID: PMC6221904 DOI: 10.3389/fvets.2018.00274] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 10/15/2018] [Indexed: 12/11/2022] Open
Abstract
Comparative medicine deals with similarities and differences between veterinary and human medicine. All mammals share most basic cellular and molecular mechanisms, thus justifying murine animal models in a translational perspective; yet “mice are not men,” thus some biases can emerge when complex biological processes are concerned. Brain plasticity is a cutting-edge, expanding topic in the field of Neurosciences with important translational implications, yet, with remarkable differences among mammals, as emerging from comparative studies. In particular, adult neurogenesis (the genesis of new neurons from brain stem cell niches) is a life-long process in laboratory rodents but a vestigial, mostly postnatal remnant in humans and dolphins. Another form of “whole cell” plasticity consisting of a population of “immature” neurons which are generated prenatally but continue to express markers of immaturity during adulthood has gained interest more recently, as a reservoir of young neurons in the adult brain. The distribution of the immature neurons also seems quite heterogeneous among different animal species, being confined within the paleocortex in rodents while extending into neocortex in other mammals. A recent study carried out in sheep, definitely showed that gyrencephalic, large-sized brains do host higher amounts of immature neurons, also involving subcortical, white, and gray matter regions. Hence, “whole cell” plasticity such as adult neurogenesis and immature neurons are biological processes which, as a whole, cannot be studied exclusively in laboratory rodents, but require investigation in comparative medicine, involving large-sized, long-living mammals, in order to gain insights for translational purposes.
Collapse
Affiliation(s)
- Chiara La Rosa
- Neuroscience Institute Cavalieri Ottolenghi, Turin, Italy.,Department of Veterinary Sciences, University of Turin, Turin, Italy
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi, Turin, Italy.,Department of Veterinary Sciences, University of Turin, Turin, Italy
| |
Collapse
|
61
|
Adult Hippocampal Neurogenesis: A Coming-of-Age Story. J Neurosci 2018; 38:10401-10410. [PMID: 30381404 DOI: 10.1523/jneurosci.2144-18.2018] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/21/2018] [Accepted: 10/23/2018] [Indexed: 12/20/2022] Open
Abstract
What has become standard textbook knowledge over the last decade was a hotly debated matter a decade earlier: the proposition that new neurons are generated in the adult mammalian CNS. The early discovery by Altman and colleagues in the 1960s was vulnerable to criticism due to the lack of technical strategies for unequivocal demonstration, quantification, and physiological analysis of newly generated neurons in adult brain tissue. After several technological advancements had been made in the field, we published a paper in 1996 describing the generation of new neurons in the adult rat brain and the decline of hippocampal neurogenesis during aging. The paper coincided with the publication of several other studies that together established neurogenesis as a cellular mechanism in the adult mammalian brain. In this Progressions article, which is by no means a comprehensive review, we recount our personal view of the initial setting that led to our study and we discuss some of its implications and developments that followed. We also address questions that remain regarding the regulation and function of neurogenesis in the adult mammalian brain, in particular the existence of neurogenesis in the adult human brain.
Collapse
|
62
|
Imam A, Bhagwandin A, Ajao MS, Spocter MA, Ihunwo AO, Manger PR. The brain of the tree pangolin (Manis tricuspis
). II. The olfactory system. J Comp Neurol 2018; 526:2548-2569. [DOI: 10.1002/cne.24510] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/27/2018] [Accepted: 07/27/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Aminu Imam
- Faculty of Health Sciences, University of the Witwatersrand; School of Anatomical Sciences; Republic of South Africa
- Department of Anatomy, Faculty of Basic Medical Sciences; College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Adhil Bhagwandin
- Faculty of Health Sciences, University of the Witwatersrand; School of Anatomical Sciences; Republic of South Africa
| | - Moyosore S. Ajao
- Department of Anatomy, Faculty of Basic Medical Sciences; College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Muhammed A. Spocter
- Faculty of Health Sciences, University of the Witwatersrand; School of Anatomical Sciences; Republic of South Africa
- Department of Anatomy; Des Moines University; Iowa
| | - Amadi O. Ihunwo
- Faculty of Health Sciences, University of the Witwatersrand; School of Anatomical Sciences; Republic of South Africa
| | - Paul R. Manger
- Faculty of Health Sciences, University of the Witwatersrand; School of Anatomical Sciences; Republic of South Africa
| |
Collapse
|
63
|
França TFA. The evolutionary significance of hippocampal neurogenesis. Eur J Neurosci 2018; 48:2945-2947. [PMID: 30192992 DOI: 10.1111/ejn.14144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/21/2018] [Accepted: 08/28/2018] [Indexed: 01/20/2023]
Abstract
Hippocampal neurogenesis (HN) has been implicated in a variety of hippocampus-dependent behaviors in the laboratory but its evolutionary significance is still debated. Some authors have argued that HN is an adaptation while others argued it is an atavism. However, recent analyses lead to the conclusion that HN likely evolved concurrently with the dentate gyrus itself, both being dependent on a migration of neural stem and progenitor cells out of the periventricular zone that occurs during development. This may render the previous debates obsolete, as selective pressure was likely acting upon the mammalian dentate gyrus itself, with neurogenesis being a mere spandrel in dentate gyrus' evolution.
Collapse
Affiliation(s)
- Thiago F A França
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil
| |
Collapse
|
64
|
Abati E, Bresolin N, Comi GP, Corti S. Preconditioning and Cellular Engineering to Increase the Survival of Transplanted Neural Stem Cells for Motor Neuron Disease Therapy. Mol Neurobiol 2018; 56:3356-3367. [PMID: 30120734 DOI: 10.1007/s12035-018-1305-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 08/07/2018] [Indexed: 12/11/2022]
Abstract
Despite the extensive research effort that has been made in the field, motor neuron diseases, namely, amyotrophic lateral sclerosis and spinal muscular atrophies, still represent an overwhelming cause of morbidity and mortality worldwide. Exogenous neural stem cell-based transplantation approaches have been investigated as multifaceted strategies to both protect and repair upper and lower motor neurons from degeneration and inflammation. Transplanted neural stem cells (NSCs) exert their beneficial effects not only through the replacement of damaged cells but also via bystander immunomodulatory and neurotrophic actions. Notwithstanding these promising findings, the clinical translatability of such techniques is jeopardized by the limited engraftment success and survival of transplanted cells within the hostile disease microenvironment. To overcome this obstacle, different methods to enhance graft survival, stability, and therapeutic potential have been developed, including environmental stress preconditioning, biopolymers scaffolds, and genetic engineering. In this review, we discuss current engineering techniques aimed at the exploitation of the migratory, proliferative, and secretive capacity of NSCs and their relevance for the therapeutic arsenal against motor neuron disorders and other neurological disorders.
Collapse
Affiliation(s)
- Elena Abati
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), Neuroscience Section, University of Milan, Milan, Italy
| | - Nereo Bresolin
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), Neuroscience Section, University of Milan, Milan, Italy.,Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, via F. Sforza 35, 20122, Milan, Italy
| | - Giacomo Pietro Comi
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), Neuroscience Section, University of Milan, Milan, Italy.,Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, via F. Sforza 35, 20122, Milan, Italy
| | - Stefania Corti
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), Neuroscience Section, University of Milan, Milan, Italy. .,Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, via F. Sforza 35, 20122, Milan, Italy.
| |
Collapse
|
65
|
Reid GA, Geula C, Darvesh S. The cholinergic system in the basal forebrain of the Atlantic white-sided dolphin (Lagenorhynchus acutus). J Comp Neurol 2018; 526:1910-1926. [PMID: 29700823 DOI: 10.1002/cne.24460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/05/2018] [Accepted: 04/17/2018] [Indexed: 11/12/2022]
Abstract
The basal forebrain (BFB) cholinergic neurotransmitter system is important in a number of brain functions including attention, memory, and the sleep-wake cycle. The size of this region has been linked to the increase in encephalization of the brain in a number of species. Cetaceans, particularly those belonging to the family Delphinidae, have a relatively large brain compared to its body size and it is expected that the cholinergic BFB in the dolphin would be a prominent feature. However, this has not yet been explored in detail. This study examines and maps the neuroanatomy and cholinergic chemoarchitecture of the BFB in the Atlantic white-sided dolphin (Lagenorhynchus acutus). As in some other mammals, the BFB in this species is a prominent structure along the medioventral surface of the brain. The parcellation and distribution of cholinergic neural elements of the dolphin BFB was comparable to that observed in other mammals in that it has a medial septal nucleus, a nucleus of the vertical limb of the diagonal band of Broca, a nucleus of the horizontal limb of the diagonal band of Broca, and a nucleus basalis of Meynert. The observed BFB cholinergic system of this dolphin is consistent with evolutionarily conserved and important functions for survival.
Collapse
Affiliation(s)
- George Andrew Reid
- Department of Medical Neuroscience, Halifax, Dalhousie University, Nova Scotia, Canada.,Marine Animal Response Society, Halifax, Nova Scotia, Canada
| | - Changiz Geula
- Cognitive Neurology and Alzheimer's Disease Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Sultan Darvesh
- Department of Medical Neuroscience, Halifax, Dalhousie University, Nova Scotia, Canada.,Department of Medicine (Neurology and Geriatric Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
66
|
Parolisi R, Cozzi B, Bonfanti L. Humans and Dolphins: Decline and Fall of Adult Neurogenesis. Front Neurosci 2018; 12:497. [PMID: 30079011 PMCID: PMC6062615 DOI: 10.3389/fnins.2018.00497] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/02/2018] [Indexed: 02/06/2023] Open
Abstract
Pre-clinical research is carried out on animal models, mostly laboratory rodents, with the ultimate aim of translating the acquired knowledge to humans. In the last decades, adult neurogenesis (AN) has been intensively studied since it is viewed as a tool for fostering brain plasticity, possibly repair. Yet, occurrence, location, and rate of AN vary among mammals: the capability for constitutive neuronal production is substantially reduced when comparing small-brained, short living (laboratory rodents) and large-brained, long-living species (humans, dolphins). Several difficulties concerning scarce availability of fresh tissues, technical limits and ethical concerns did contribute in delaying and diverting the achievement of the picture of neurogenic plasticity in large-brained mammals. Some reports appeared in the last few years, starting to shed more light on this issue. Despite technical limits, data from recent studies mostly converge to indicate that neurogenesis is vestigial, or possibly absent, in regions of the adult human brain where in rodents neuronal addition continues into adult life. Analyses carried out in dolphins, mammals devoid of olfaction, but descendant of ancestors provided with olfaction, has shown disappearance of neurogenesis in both neonatal and adult individuals. Heterogeneity in mammalian structural plasticity remains largely underestimated by scientists focusing their research in rodents. Comparative studies are the key to understand the function of AN and the possible translational significance of neuronal replacement in humans. Here, we summarize comparative studies on AN and discuss the evolutionary implications of variations on the recruitment of new neurons in different regions and different species.
Collapse
Affiliation(s)
- Roberta Parolisi
- NICO - Neuroscience Institute Cavalieri Ottolenghi, Turin, Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padua, Padua, Italy
| | - Luca Bonfanti
- NICO - Neuroscience Institute Cavalieri Ottolenghi, Turin, Italy.,Department of Veterinary Sciences, University of Turin, Turin, Italy
| |
Collapse
|
67
|
França TFA. Plasticity and redundancy in the integration of adult born neurons in the hippocampus. Neurobiol Learn Mem 2018; 155:136-142. [PMID: 30031119 DOI: 10.1016/j.nlm.2018.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/05/2018] [Accepted: 07/17/2018] [Indexed: 01/05/2023]
Abstract
Hippocampal neurogenesis (HN) is an extreme form of plasticity that inevitably rewires the hippocampal circuit and this rewiring was put forward as a possible mechanism for neurogenesis' behavioral effects. Here, I critically evaluate multiple lines of evidence to argue that structural plasticity induced by HN is, to a large extent, functionally redundant and thus has limited impact on behavior. The associative plasticity rules along with properties of immature neurons should only allow the survival of new neurons whose pre and postsynaptic partners have correlated activity, leading to functional redundancy. Moreover, non-redundant rewiring, even with its computational benefits, would impair meaningful communication between the hippocampus and other brain regions. This implies that associative plasticity rules constrain structural plasticity induced by neurogenesis, allowing the brain to balance plasticity and stability to maintain proper functioning. It also implies that behavioral effects of HN are mediated by other mechanisms apart from circuit rewiring.
Collapse
Affiliation(s)
- Thiago F A França
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil; Curso de graduação em Ciências Biológicas, Universidade Federal do Rio Grande -FURG, Rio Grande, RS, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil.
| |
Collapse
|
68
|
McDonald RP, Vickaryous MK. Evidence for neurogenesis in the medial cortex of the leopard gecko, Eublepharis macularius. Sci Rep 2018; 8:9648. [PMID: 29941970 PMCID: PMC6018638 DOI: 10.1038/s41598-018-27880-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/12/2018] [Indexed: 12/23/2022] Open
Abstract
Although lizards are often described as having robust neurogenic abilities, only a handful of the more than 6300 species have been explored. Here, we provide the first evidence of homeostatic neurogenesis in the leopard gecko (Eublepharis macularius). We focused our study on the medial cortex, homologue of the mammalian hippocampal formation. Using immunostaining, we identified proliferating pools of neural stem/progenitor cells within the sulcus septomedialis, the pseudostratified ventricular zone adjacent to the medial cortex. Consistent with their identification as radial glia, these cells expressed SOX2, glial fibrillary acidic protein, and Vimentin, and demonstrated a radial morphology. Using a 5-bromo-2′-deoxyuridine cell tracking strategy, we determined that neuroblast migration from the ventricular zone to the medial cortex takes ~30-days, and that newly generated neuronal cells survived for at least 140-days. We also found that cell proliferation within the medial cortex was not significantly altered following rupture of the tail spinal cord (as a result of the naturally evolved process of caudal autotomy). We conclude that the sulcus septomedialis of the leopard gecko demonstrates all the hallmarks of a neurogenic niche.
Collapse
Affiliation(s)
- Rebecca P McDonald
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Matthew K Vickaryous
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
| |
Collapse
|
69
|
Lebedev MA, Ossadtchi A. Commentary: Spatial Olfactory Learning Contributes to Place Field Formation in the Hippocampus. Front Syst Neurosci 2018; 12:8. [PMID: 29692712 PMCID: PMC5902690 DOI: 10.3389/fnsys.2018.00008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/12/2018] [Indexed: 11/18/2022] Open
Affiliation(s)
- Mikhail A Lebedev
- Department of Neurobiology, Duke University, Durham, NC, United States.,Center for Bioelectric Interfaces of the Institute for Cognitive Neuroscience of the National Research University Higher School of Economics, Moscow, Russia
| | - Alexei Ossadtchi
- Center for Bioelectric Interfaces of the Institute for Cognitive Neuroscience of the National Research University Higher School of Economics, Moscow, Russia
| |
Collapse
|
70
|
Olateju OI, Spocter MA, Patzke N, Ihunwo AO, Manger PR. Hippocampal neurogenesis in the C57BL/6J mice at early adulthood following prenatal alcohol exposure. Metab Brain Dis 2018; 33:397-410. [PMID: 29164372 DOI: 10.1007/s11011-017-0156-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/15/2017] [Indexed: 01/21/2023]
Abstract
We examined the effect of chronic prenatal alcohol exposure (PAE) on the process of adult neurogenesis in C57BL/6J mice at early adulthood (PND 56). Pregnant mice, and their in utero litters, were exposed to alcohol, through oral gavage, on gestational days 7-16, with recorded blood alcohol concentrations averaging 184 mg/dL (CA group). Two control groups, sucrose (CAc) and non-treated (NTc) control groups were also examined. The brains of pups at PND 56 from each experimental group were sectioned in a sagittal plane, and stained for Nissl substance with cresyl violet, and immunostained for Ki-67 which labels proliferative cells and doublecortin (DCX) for immature neurons. Morphologically, the neurogenic pattern was identical in all three groups studied. Populations of Ki-67 immunopositive cells in the dentate gyrus were not statistically significantly different between the experimental groups and there were no differences between the sexes. Thus, the PAE in this study does not appear to have a strong effect on the proliferative process in the adult hippocampus. In contrast, the numbers of immature neurons, labeled with DCX, was statistically significantly lower in the prenatal alcohol exposed mice compared with the two control groups. Alcohol significantly lowered the number of DCX hippocampal cells in the male mice, but not in the female mice. This indicates that the PAE appears to lower the rate of conversion of proliferative cells to immature neurons and this effect of alcohol is sexually dimorphic. This lowered number of immature neurons in the hippocampus appears to mirror hippocampal dysfunctions observed in FASD children.
Collapse
Affiliation(s)
- Oladiran I Olateju
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa.
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
- Department of Anatomy, Des Moines University, Des Moines, IA, 50312, USA
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| |
Collapse
|
71
|
Sorrells SF, Paredes MF, Cebrian-Silla A, Sandoval K, Qi D, Kelley KW, James D, Mayer S, Chang J, Auguste KI, Chang E, Gutierrez Martin AJ, Kriegstein AR, Mathern GW, Oldham MC, Huang EJ, Garcia-Verdugo JM, Yang Z, Alvarez-Buylla A. Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults. Nature 2018; 555:377-381. [PMID: 29513649 PMCID: PMC6179355 DOI: 10.1038/nature25975] [Citation(s) in RCA: 902] [Impact Index Per Article: 150.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 02/06/2018] [Indexed: 12/19/2022]
Abstract
New neurons continue to be generated in the subgranular zone of the dentate gyrus of the adult mammalian hippocampus. This process has been linked to learning and memory, stress and exercise, and is thought to be altered in neurological disease. In humans, some studies have suggested that hundreds of new neurons are added to the adult dentate gyrus every day, whereas other studies find many fewer putative new neurons. Despite these discrepancies, it is generally believed that the adult human hippocampus continues to generate new neurons. Here we show that a defined population of progenitor cells does not coalesce in the subgranular zone during human fetal or postnatal development. We also find that the number of proliferating progenitors and young neurons in the dentate gyrus declines sharply during the first year of life and only a few isolated young neurons are observed by 7 and 13 years of age. In adult patients with epilepsy and healthy adults (18-77 years; n = 17 post-mortem samples from controls; n = 12 surgical resection samples from patients with epilepsy), young neurons were not detected in the dentate gyrus. In the monkey (Macaca mulatta) hippocampus, proliferation of neurons in the subgranular zone was found in early postnatal life, but this diminished during juvenile development as neurogenesis decreased. We conclude that recruitment of young neurons to the primate hippocampus decreases rapidly during the first years of life, and that neurogenesis in the dentate gyrus does not continue, or is extremely rare, in adult humans. The early decline in hippocampal neurogenesis raises questions about how the function of the dentate gyrus differs between humans and other species in which adult hippocampal neurogenesis is preserved.
Collapse
Affiliation(s)
- Shawn F. Sorrells
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurological Surgery, University of California San Francisco, California 94143, USA
| | - Mercedes F. Paredes
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurology, University of California San Francisco, California 94143, USA
| | - Arantxa Cebrian-Silla
- Laboratorio de Neurobiología Comparada. Instituto Cavanilles. Universidad de Valencia, CIBERNED, Valencia, 46980, Spain
| | - Kadellyn Sandoval
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurology, University of California San Francisco, California 94143, USA
| | - Dashi Qi
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, P.R. 200032 China
| | - Kevin W. Kelley
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
| | - David James
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
| | - Simone Mayer
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurology, University of California San Francisco, California 94143, USA
| | - Julia Chang
- David Geffen School of Medicine, Department of Neurosurgery, Intellectual Development and Disabilities Research Center, University of California Los Angeles, California USA
| | - Kurtis I. Auguste
- Department of Neurological Surgery, University of California San Francisco, California 94143, USA
| | - Edward Chang
- Department of Neurological Surgery, University of California San Francisco, California 94143, USA
| | | | - Arnold R. Kriegstein
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurology, University of California San Francisco, California 94143, USA
| | - Gary W. Mathern
- Departments of Neurosurgery and Psychiatry & BioBehavioral Medicine, David Geffen School of Medicine, University of California Los Angeles, California USA
| | - Michael C. Oldham
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurological Surgery, University of California San Francisco, California 94143, USA
| | - Eric J. Huang
- Department of Pathology, University of California San Francisco, California 94143, USA
| | - Jose Manuel Garcia-Verdugo
- Laboratorio de Neurobiología Comparada. Instituto Cavanilles. Universidad de Valencia, CIBERNED, Valencia, 46980, Spain
| | - Zhengang Yang
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, P.R. 200032 China
| | - Arturo Alvarez-Buylla
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
- Department of Neurological Surgery, University of California San Francisco, California 94143, USA
| |
Collapse
|
72
|
Hecker N, Sharma V, Hiller M. Transition to an Aquatic Habitat Permitted the Repeated Loss of the Pleiotropic KLK8 Gene in Mammals. Genome Biol Evol 2018; 9:3179-3188. [PMID: 29145610 PMCID: PMC5716171 DOI: 10.1093/gbe/evx239] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2017] [Indexed: 01/15/2023] Open
Abstract
Kallikrein related peptidase 8 (KLK8; also called neuropsin) is a serine protease that plays distinct roles in the skin and hippocampus. In the skin, KLK8 influences keratinocyte proliferation and desquamation, and activates antimicrobial peptides in sweat. In the hippocampus, KLK8 affects memory acquisition. Here, we examined the evolution of KLK8 in mammals and discovered that, out of 70 placental mammals, KLK8 is exclusively lost in three independent fully-aquatic lineages, comprising dolphin, killer whale, minke whale, and manatee. In addition, while the sperm whale has an intact KLK8 reading frame, the gene evolves neutrally in this species. We suggest that the distinct functions of KLK8 likely became obsolete in the aquatic environment, leading to the subsequent loss of KLK8 in several fully-aquatic mammalian lineages. First, the cetacean and manatee skin lacks sweat glands as an adaptation to the aquatic environment, which likely made the epidermal function of KLK8 obsolete. Second, cetaceans and manatees exhibit a proportionally small hippocampus, which may have rendered the hippocampal functions of KLK8 obsolete. Together, our results shed light on the genomic changes that correlate with skin and neuroanatomical differences of aquatic mammals, and show that even pleiotropic genes can be lost during evolution if an environmental change nullifies the need for the different functions of such genes.
Collapse
Affiliation(s)
- Nikolai Hecker
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Virag Sharma
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| |
Collapse
|
73
|
Abstract
The brain is a dynamic organ of the biological renaissance due to the existence of neuroplasticity. Adult neurogenesis abides by every aspect of neuroplasticity in the intact brain and contributes to neural regeneration in response to brain diseases and injury. The occurrence of adult neurogenesis has unequivocally been witnessed in human subjects, experimental and wildlife research including rodents, bats and cetaceans. Adult neurogenesis is a complex cellular process, in which generation of neuroblasts namely, neuroblastosis appears to be an integral process that occur in the limbic system and basal ganglia in addition to the canonical neurogenic niches. Neuroblastosis can be regulated by various factors and contributes to different functions of the brain. The characteristics and fate of neuroblasts have been found to be different among mammals regardless of their cognitive functions. Recently, regulation of neuroblastosis has been proposed for the sensorimotor interface and regenerative neuroplasticity of the adult brain. Hence, the understanding of adult neurogenesis at the functional level of neuroblasts requires a great scientific attention. Therefore, this mini-review provides a glimpse into the conceptual development of neuroplasticity, discusses the possible role of different types of neuroblasts and signifies neuroregenerative failure as a potential cause of dementia.
Collapse
Affiliation(s)
- Mahesh Kandasamy
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu; Faculty Recharge Programme, University Grants Commission (UGC-FRP), New Delhi, India
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University; Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria
| |
Collapse
|
74
|
Fasemore TM, Patzke N, Kaswera-Kyamakya C, Gilissen E, Manger PR, Ihunwo AO. The Distribution of Ki-67 and Doublecortin-Immunopositive Cells in the Brains of Three Strepsirrhine Primates: Galago demidoff, Perodicticus potto, and Lemur catta. Neuroscience 2017; 372:46-57. [PMID: 29289719 DOI: 10.1016/j.neuroscience.2017.12.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 12/18/2022]
Abstract
This study investigated the pattern of adult neurogenesis throughout the brains of three prosimian primate species using immunohistochemical techniques for endogenous markers of this neural process. Two species, Galago demidoff and Perodicticus potto, were obtained from wild populations in the primary rainforest of central Africa, while one species, Lemur catta, was captive-bred. Two brains from each species, perfusion-fixed with 4% paraformaldehyde, were sectioned (50 µm section thickness) in sagittal and coronal planes. Using Ki-67 and doublecortin (DCX) antibodies, proliferating cells and immature neurons were identified in the two canonical neurogenic sites of mammals, the subventricular zone of the lateral ventricle (SVZ) giving rise to the rostral migratory stream (RMS), and the subgranular zone of the dentate gyrus of the hippocampus. In addition a temporal migratory stream (TMS), emerging from the temporal horn of the lateral ventricle to supply the piriform cortex and adjacent brain regions with new neurons, was also evident in the three prosimian species. While no Ki-67-immunoreactive cells were observed in the cerebellum, DCX-immunopositive cells were observed in the cerebellar cortex of all three species. These findings are discussed in a phylogenetic context.
Collapse
Affiliation(s)
- Thandi M Fasemore
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Institute for International Collaborations, Department of Biological Science, Hokkaido University, Sapporo, Japan
| | | | - Emmanuel Gilissen
- Department of African Zoology, Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium; Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels 1070, Belgium; Department of Anthropology, University of Arkansas, Fayetteville, AR, United States
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| |
Collapse
|
75
|
Ngwenya A, Patzke N, Herculano-Houzel S, Manger PR. Potential Adult Neurogenesis in the Telencephalon and Cerebellar Cortex of the Nile Crocodile Revealed with Doublecortin Immunohistochemistry. Anat Rec (Hoboken) 2017; 301:659-672. [DOI: 10.1002/ar.23738] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 06/26/2017] [Accepted: 07/31/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Ayanda Ngwenya
- School of Anatomical Sciences, Faculty of Health Sciences; University of the Witwatersrand, 7 York Road, Parktown; Johannesburg 2193 Republic of South Africa
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences; University of the Witwatersrand, 7 York Road, Parktown; Johannesburg 2193 Republic of South Africa
| | - Suzana Herculano-Houzel
- Department of Psychology; Vanderbilt University; Nashville Tennessee
- Department of Biological Sciences; Vanderbilt University; Nashville Tennessee
| | - Paul R. Manger
- School of Anatomical Sciences, Faculty of Health Sciences; University of the Witwatersrand, 7 York Road, Parktown; Johannesburg 2193 Republic of South Africa
| |
Collapse
|
76
|
Review: adult neurogenesis contributes to hippocampal plasticity. Cell Tissue Res 2017; 373:693-709. [PMID: 29185071 DOI: 10.1007/s00441-017-2735-4] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/27/2017] [Indexed: 12/18/2022]
Abstract
Adult hippocampal neurogenesis is the process by which new functional neurons are added to the adult dentate gyrus of the hippocampus. Animal studies have shown that the degree of adult hippocampal neurogenesis is regulated by local environmental cues as well as neural network activities. Furthermore, accumulating evidence has suggested that adult hippocampal neurogenesis plays prominent roles in hippocampus-dependent brain functions. In this review, we summarize the mechanisms underlying the regulation of adult hippocampal neurogenesis at various developmental stages and propose how adult-born neurons contribute to structural and functional hippocampal plasticity.
Collapse
|
77
|
Limacher-Burrell A, Bhagwandin A, Maseko BC, Manger PR. Nuclear organization of the African elephant (Loxodonta africana) amygdaloid complex: an unusual mammalian amygdala. Brain Struct Funct 2017; 223:1191-1216. [PMID: 29098403 DOI: 10.1007/s00429-017-1555-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/24/2017] [Indexed: 11/25/2022]
Abstract
Here we describe the nuclear organization of the African elephant amygdaloid complex using Nissl, myelin, and a range of immunohistochemical stains. The African elephant is thought to exhibit many affect-laden and social-empathic behaviours; however, to date the amygdaloid complex, which is the generator of emotional states of the brain is yet to be fully explored in the elephants. For the most part, the amygdaloid complex of the African elephant is similar to that observed in other mammals in terms of the presence of nuclei and their topological relationships; however, we did observe several specific differences in amygdaloid organization. The elephant amygdala has undergone rotation in both the coronal and sagittal planes, seemingly associated with the expansion of the temporal lobe. Numerous scalloped cell clusters, termed glomeruli, forming the intermediate nuclei of the basal, accessory basal and central nuclear groups, were occupied by structures immunopositive to doublecortin. The nuclei typically associated with the accessory olfactory system (posterior cortical nucleus and medial nuclear complex) were absent from the elephant amygdala. The anterior cortical nucleus is very large and appears to be comprised of two subdivisions. The lateral nuclear complex is expanded and has two novel subdivisions. The amygdalohippocampal area appears relatively enlarged. The numerous shared and derived characters make the elephant amygdaloid complex very unusual and unique amongst mammals, but the derived characters appear to relate to observed elephant affect-laden behaviours.
Collapse
Affiliation(s)
- Aude'Marie Limacher-Burrell
- School of Anatomical Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Busisiwe C Maseko
- School of Anatomical Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa.
| |
Collapse
|
78
|
Martínez-Cerdeño V, García-Moreno F, Tosches MA, Csillag A, Manger PR, Molnár Z. Update on forebrain evolution: From neurogenesis to thermogenesis. Semin Cell Dev Biol 2017; 76:15-22. [PMID: 28964836 DOI: 10.1016/j.semcdb.2017.09.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 01/25/2023]
Abstract
Comparative developmental studies provide growing understanding of vertebrate forebrain evolution. This short review directs the spotlight to some newly emerging aspects, including the evolutionary origin of the proliferative region known as the subventricular zone (SVZ) and of intermediate progenitor cells (IPCs) that populate the SVZ, neural circuits that originated within homologous regions across all amniotes, and the role of thermogenesis in the acquisition of an increased brain size. These data were presented at the 8th European Conference on Comparative Neurobiology.
Collapse
Affiliation(s)
- Verónica Martínez-Cerdeño
- Department of Pathology and Laboratory Medicine, UC Davis, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, USA; MIND Institute, UC Davis School of Medicine, CA, USA.
| | - Fernando García-Moreno
- Achucarro Basque Center for Neuroscience, Parque Científico UPV/EHU Edif. Sede, E-48940 Leioa, Spain
| | | | - András Csillag
- Department of Anatomy, Histology and Embryology, Semmelweis University, Faculty of Medicine, Budapest, Hungary
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of Witwatersrand, South Africa
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
| |
Collapse
|
79
|
Fox KCR, Muthukrishna M, Shultz S. The social and cultural roots of whale and dolphin brains. Nat Ecol Evol 2017; 1:1699-1705. [PMID: 29038481 DOI: 10.1038/s41559-017-0336-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 09/01/2017] [Indexed: 02/04/2023]
Abstract
Encephalization, or brain expansion, underpins humans' sophisticated social cognition, including language, joint attention, shared goals, teaching, consensus decision-making and empathy. These abilities promote and stabilize cooperative social interactions, and have allowed us to create a 'cognitive' or 'cultural' niche and colonize almost every terrestrial ecosystem. Cetaceans (whales and dolphins) also have exceptionally large and anatomically sophisticated brains. Here, by evaluating a comprehensive database of brain size, social structures and cultural behaviours across cetacean species, we ask whether cetacean brains are similarly associated with a marine cultural niche. We show that cetacean encephalization is predicted by both social structure and by a quadratic relationship with group size. Moreover, brain size predicts the breadth of social and cultural behaviours, as well as ecological factors (diversity of prey types and to a lesser extent latitudinal range). The apparent coevolution of brains, social structure and behavioural richness of marine mammals provides a unique and striking parallel to the large brains and hyper-sociality of humans and other primates. Our results suggest that cetacean social cognition might similarly have arisen to provide the capacity to learn and use a diverse set of behavioural strategies in response to the challenges of social living.
Collapse
Affiliation(s)
- Kieran C R Fox
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Michael Muthukrishna
- Department of Psychological and Behavioural Science, London School of Economics and Political Science, London, WC2A 2AE, UK.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Susanne Shultz
- School of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PL, UK.
| |
Collapse
|
80
|
Bhagwandin A, Haagensen M, Manger PR. The Brain of the Black ( Diceros bicornis) and White ( Ceratotherium simum) African Rhinoceroses: Morphology and Volumetrics from Magnetic Resonance Imaging. Front Neuroanat 2017; 11:74. [PMID: 28912691 PMCID: PMC5583206 DOI: 10.3389/fnana.2017.00074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/15/2017] [Indexed: 12/22/2022] Open
Abstract
The morphology and volumetrics of the understudied brains of two iconic large terrestrial African mammals: the black (Diceros bicornis) and white (Ceratotherium simum) rhinoceroses are described. The black rhinoceros is typically solitary whereas the white rhinoceros is social, and both are members of the Perissodactyl order. Here, we provide descriptions of the surface of the brain of each rhinoceros. For both species, we use magnetic resonance images (MRI) to develop a description of the internal anatomy of the rhinoceros brain and to calculate the volume of the amygdala, cerebellum, corpus callosum, hippocampus, and ventricular system as well as to determine the gyrencephalic index. The morphology of both black and white rhinoceros brains is very similar to each other, although certain minor differences, seemingly related to diet, were noted, and both brains evince the general anatomy of the mammalian brain. The rhinoceros brains display no obvious neuroanatomical specializations in comparison to other mammals previously studied. In addition, the volumetric analyses indicate that the size of the various regions of the rhinoceros brain measured, as well as the extent of gyrification, are what would be predicted for a mammal with their brain mass when compared allometrically to previously published data. We conclude that the brains of the black and white rhinoceros exhibit a typically mammalian organization at a superficial level, but histological studies may reveal specializations of interest in relation to rhinoceros behavior.
Collapse
Affiliation(s)
- Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburg, South Africa
| | - Mark Haagensen
- Department of Radiology, Wits Donald Gordon Medical Centre, University of the WitwatersrandJohannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburg, South Africa
| |
Collapse
|
81
|
Lipp HP. Evolutionary Shaping of Adult Hippocampal Neurogenesis in Mammals-Cognitive Gain or Developmental Priming of Personality Traits? Front Neurosci 2017; 11:420. [PMID: 28785199 PMCID: PMC5519572 DOI: 10.3389/fnins.2017.00420] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/05/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hans-Peter Lipp
- Institute of Evolutionary Medicine, University of ZurichZurich, Switzerland.,Institute of Anatomy, University of ZurichZurich, Switzerland.,Department of Physiology, School of Laboratory Medicine, University of Kwazulu-NatalDurban, South Africa
| |
Collapse
|
82
|
Imam A, Ajao MS, Bhagwandin A, Ihunwo AO, Manger PR. The brain of the tree pangolin (Manis tricuspis
). I. General appearance of the central nervous system. J Comp Neurol 2017; 525:2571-2582. [DOI: 10.1002/cne.24222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Aminu Imam
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
- Department of Anatomy; Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Moyosore S. Ajao
- Department of Anatomy; Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin; Ilorin Nigeria
| | - Adhil Bhagwandin
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
| | - Amadi O. Ihunwo
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
| | - Paul R. Manger
- School of Anatomical Sciences; Faculty of Health Sciences, University of the Witwatersrand; Johannesburg Republic of South Africa
| |
Collapse
|
83
|
Parolisi R, Cozzi B, Bonfanti L. Non-neurogenic SVZ-like niche in dolphins, mammals devoid of olfaction. Brain Struct Funct 2017; 222:2625-2639. [PMID: 28238073 DOI: 10.1007/s00429-016-1361-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/22/2016] [Indexed: 11/29/2022]
Abstract
Adult neurogenesis has been implicated in brain plasticity and brain repair. In mammals, it is mostly restricted to specific brain regions and specific physiological functions. The function and evolutionary history of mammalian adult neurogenesis has been elusive so far. The largest neurogenic site in mammals (subventricular zone, SVZ) generates neurons destined to populate the olfactory bulb. The SVZ neurogenic activity appears to be related to the dependence of the species on olfaction since it occurs at high rates throughout life in animals strongly dependent on this function for their survival. Indeed, it dramatically decreases in humans, who do not depend so much on it. This study investigates whether the SVZ neurogenic site exists in mammals devoid of olfaction and olfactory brain structures, such as dolphins. Our results demonstate that a small SVZ-like region persists in these aquatic mammals. However, this region seems to have lost its neurogenic capabilities since neonatal stages. In addition, instead of the typical newly generated neuroblasts, some mature neurons were observed in the dolphin SVZ. Since cetaceans evolved from terrestrial ancestors, non-neurogenic SVZ may indicate extinction of adult neurogenesis in the absence of olfactory function, with the retention of an SVZ-like anatomical region either vestigial or of still unknown role.
Collapse
Affiliation(s)
- Roberta Parolisi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy.,Department of Veterinary Sciences, University of Turin, Via Leonardo da Vinci, 44, 10095, Grugliasco, TO, Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, Italy
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy. .,Department of Veterinary Sciences, University of Turin, Via Leonardo da Vinci, 44, 10095, Grugliasco, TO, Italy.
| |
Collapse
|
84
|
Sleep and Development in Genetically Tractable Model Organisms. Genetics 2017; 203:21-33. [PMID: 27183564 DOI: 10.1534/genetics.116.189589] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/21/2016] [Indexed: 12/21/2022] Open
Abstract
Sleep is widely recognized as essential, but without a clear singular function. Inadequate sleep impairs cognition, metabolism, immune function, and many other processes. Work in genetic model systems has greatly expanded our understanding of basic sleep neurobiology as well as introduced new concepts for why we sleep. Among these is an idea with its roots in human work nearly 50 years old: sleep in early life is crucial for normal brain maturation. Nearly all known species that sleep do so more while immature, and this increased sleep coincides with a period of exuberant synaptogenesis and massive neural circuit remodeling. Adequate sleep also appears critical for normal neurodevelopmental progression. This article describes recent findings regarding molecular and circuit mechanisms of sleep, with a focus on development and the insights garnered from models amenable to detailed genetic analyses.
Collapse
|
85
|
Ihunwo AO, Tembo LH, Dzamalala C. The dynamics of adult neurogenesis in human hippocampus. Neural Regen Res 2016; 11:1869-1883. [PMID: 28197172 PMCID: PMC5270414 DOI: 10.4103/1673-5374.195278] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2016] [Indexed: 02/06/2023] Open
Abstract
The phenomenon of adult neurogenesis is now an accepted occurrence in mammals and also in humans. At least two discrete places house stem cells for generation of neurons in adult brain. These are olfactory system and the hippocampus. In animals, newly generated neurons have been directly or indirectly demonstrated to generate a significant amount of new neurons to have a functional role. However, the data in humans on the extent of this process is still scanty and such as difficult to comprehend its functional role in humans. This paper explores the available data on as extent of adult hippocampal neurogenesis in humans and makes comparison to animal data.
Collapse
Affiliation(s)
- Amadi O. Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Lackson H. Tembo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Charles Dzamalala
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
86
|
LaDage LD. Factors That Modulate Neurogenesis: A Top-Down Approach. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:184-190. [PMID: 27560485 DOI: 10.1159/000446906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although hippocampal neurogenesis in the adult brain has been conserved across the vertebrate lineage, laboratory studies have primarily examined this phenomenon in rodent models. This approach has been successful in elucidating important factors and mechanisms that can modulate rates of hippocampal neurogenesis, including hormones, environmental complexity, learning and memory, motor stimulation, and stress. However, recent studies have found that neurobiological research on neurogenesis in rodents may not easily translate to, or explain, neurogenesis patterns in nonrodent systems, particularly in species examined in the field. This review examines some of the evolutionary and ecological variables that may also modulate neurogenesis patterns. This 'top-down' and more naturalistic approach, which incorporates ecology and natural history, particularly of nonmodel species, may allow for a more comprehensive understanding of the functional significance of neurogenesis.
Collapse
Affiliation(s)
- Lara D LaDage
- Division of Mathematics and Natural Sciences, Penn State University Altoona, Altoona, Pa., USA
| |
Collapse
|
87
|
Chawana R, Patzke N, Alagaili AN, Bennett NC, Mohammed OB, Kaswera-Kyamakya C, Gilissen E, Ihunwo AO, Pettigrew JD, Manger PR. The Distribution of Ki-67 and Doublecortin Immunopositive Cells in the Brains of Three Microchiropteran Species, Hipposideros fuliginosus, Triaenops persicus, and Asellia tridens. Anat Rec (Hoboken) 2016; 299:1548-1560. [PMID: 27532288 DOI: 10.1002/ar.23460] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/24/2016] [Accepted: 06/09/2016] [Indexed: 01/26/2023]
Abstract
This study uses Ki-67 and doublecortin (DCX) immunohistochemistry to delineate potential neurogenic zones, migratory pathways, and terminal fields associated with adult neurogenesis in the brains of three microchiropterans. As with most mammals studied to date, the canonical subgranular and subventricular neurogenic zones were observed. Distinct labeling of newly born cells and immature neurons within the dentate gyrus of the hippocampus was observed in all species. A distinct rostral migratory stream (RMS) that appears to split around the medial aspect of the caudate nucleus was observed. These two rostral stream divisions appear to merge at the rostroventral corner of the caudate nucleus to turn and enter the olfactory bulb, where a large terminal field of immature neurons was observed. DCX immunolabeled neurons were observed mostly in the rostral neocortex, but a potential migratory stream to the neocortex was not identified. A broad swathe of newly born cells and immature neurons was found between the caudoventral division of the RMS and the piriform cortex. In addition, occasional immature neurons were observed in the amygdala and DCX-immunopositive axons were observed in the anterior commissure. While the majority of these features have been found in several mammal species, the large number of DCX immunolabeled cells found between the RMS and the piriform cortex and the presence of DCX immunostained axons in the anterior commissure are features only observed in microchiropterans and insectivores to date. In the diphyletic scenario of chiropteran evolution, these observations align the microchiropterans with the insectivores. Anat Rec, 299:1548-1560, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Richard Chawana
- School of Anatomical Sciences Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Nina Patzke
- School of Anatomical Sciences Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Abdulaziz N Alagaili
- KSU Mammals Research Chair, Department, of Zoology, College of Science, King Saud University, Box, 2455, Riyadh, 11451, Saudi Arabia.,Saudi Wildlife Authority, Riyadh, 11575, Saudi Arabia
| | - Nigel C Bennett
- KSU Mammals Research Chair, Department, of Zoology, College of Science, King Saud University, Box, 2455, Riyadh, 11451, Saudi Arabia.,Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa
| | - Osama B Mohammed
- KSU Mammals Research Chair, Department, of Zoology, College of Science, King Saud University, Box, 2455, Riyadh, 11451, Saudi Arabia
| | | | - Emmanuel Gilissen
- Department of African Zoology, Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080, Tervuren, Belgium.,Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, 1070, Belgium.,Department of Anthropology, University of Arkansas, Fayetteville, Arkansas
| | - Amadi O Ihunwo
- School of Anatomical Sciences Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa
| | - John D Pettigrew
- Queensland Brain Institute, University of Queensland, 4072, St. Lucia, Australia
| | - Paul R Manger
- School of Anatomical Sciences Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa.
| |
Collapse
|
88
|
Lipp HP, Bonfanti L. Adult Neurogenesis in Mammals: Variations and Confusions. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:205-221. [DOI: 10.1159/000446905] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mammalian adult neurogenesis has remained enigmatic. Two lines of research have emerged. One focuses on a potential repair mechanism in the human brain. The other aims at elucidating its functional role in the hippocampal formation, chiefly in cognitive processes; however, thus far it has been unsuccessful. Here, we try to recognize the sources of errors and conceptual confusion in comparative studies and neurobehavioral approaches with a focus on mice. Evolutionarily, mammalian adult neurogenesis appears as protracted juvenile neurogenesis originating from precursor cells in the secondary proliferation zones, from where newly formed cells migrate to target regions in the forebrain. This late developmental process is downregulated differentially in various brain structures depending on species and age. Adult neurogenesis declines substantially during early adulthood and persists at low levels into senescence. Short-lasting episodes in proliferation or reduction of adult neurogenesis may reflect a multitude of factors, and have been studied chiefly in mice and rats. Comparative studies face both species-specific variations in staining and technical abilities of laboratories, lacking quantification of important reference measures (e.g. granule cell number) and evaluation of maturational markers whose persistence might be functionally more relevant than proliferation rates. Likewise, the confusion about the functional role of variations in adult hippocampal neurogenesis has many causes. Prominent is an inferential statistical approach, usually with low statistical power. Interpretation is complicated by multiple theories about hippocampal function, often unrealistically extrapolating from humans to rodents. We believe that the field of mammalian adult neurogenesis needs more critical thinking, more sophisticated hypotheses, better statistical, technical and behavioral approaches, and a broader conceptual perspective incorporating comparative aspects rather than neglecting them.
Collapse
|
89
|
Meskenaite V, Krackow S, Lipp HP. Age-Dependent Neurogenesis and Neuron Numbers within the Olfactory Bulb and Hippocampus of Homing Pigeons. Front Behav Neurosci 2016; 10:126. [PMID: 27445724 PMCID: PMC4916210 DOI: 10.3389/fnbeh.2016.00126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 06/06/2016] [Indexed: 12/14/2022] Open
Abstract
Many birds are supreme long-distance navigators that develop their navigational ability in the first months after fledgling but update the memorized environmental information needed for navigation also later in life. We studied the extent of juvenile and adult neurogenesis that could provide such age-related plasticity in brain regions known to mediate different mechanisms of pigeon homing: the olfactory bulb (OB), and the triangular area of the hippocampal formation (HP tr). Newly generated neurons (visualized by doublecortin, DCX) and mature neurons were counted stereologically in 35 pigeon brains ranging from 1 to 168 months of age. At the age of 1 month, both areas showed maximal proportions of DCX positive neurons, which rapidly declined during the first year of life. In the OB, the number of DCX-positive periglomerular neurons declined further over time, but the number of mature periglomerular cells appeared unchanged. In the hippocampus, the proportion of DCX-positive neurons showed a similar decline yet to a lesser extent. Remarkably, in the triangular area of the hippocampus, the oldest birds showed nearly twice the number of neurons as compared to young adult pigeons, suggesting that adult born neurons in these regions expanded the local circuitry even in aged birds. This increase might reflect navigational experience and, possibly, expanded spatial memory. On the other hand, the decrease of juvenile neurons in the aging OB without adding new circuitry might be related to the improved attachment to the loft characterizing adult and old pigeons.
Collapse
Affiliation(s)
- Virginia Meskenaite
- Institute of Anatomy, University of ZurichZurich, Switzerland; The Interface Group, Institute of Physiology, University of ZurichZurich, Switzerland
| | - Sven Krackow
- Institute of Anatomy, University of Zurich Zurich, Switzerland
| | - Hans-Peter Lipp
- Institute of Anatomy, University of ZurichZurich, Switzerland; Department of Physiology, School of Medical Sciences, Kwazulu-Natal UniversityDurban, South Africa; Institute of Evolutionary Medicine, University of ZurichZurich, Switzerland
| |
Collapse
|
90
|
van Dijk RM, Huang SH, Slomianka L, Amrein I. Taxonomic Separation of Hippocampal Networks: Principal Cell Populations and Adult Neurogenesis. Front Neuroanat 2016; 10:22. [PMID: 27013984 PMCID: PMC4783399 DOI: 10.3389/fnana.2016.00022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/23/2016] [Indexed: 11/13/2022] Open
Abstract
While many differences in hippocampal anatomy have been described between species, it is typically not clear if they are specific to a particular species and related to functional requirements or if they are shared by species of larger taxonomic units. Without such information, it is difficult to infer how anatomical differences may impact on hippocampal function, because multiple taxonomic levels need to be considered to associate behavioral and anatomical changes. To provide information on anatomical changes within and across taxonomic ranks, we present a quantitative assessment of hippocampal principal cell populations in 20 species or strain groups, with emphasis on rodents, the taxonomic group that provides most animals used in laboratory research. Of special interest is the importance of adult hippocampal neurogenesis (AHN) in species-specific adaptations relative to other cell populations. Correspondence analysis of cell numbers shows that across taxonomic units, phylogenetically related species cluster together, sharing similar proportions of principal cell populations. CA3 and hilus are strong separators that place rodent species into a tight cluster based on their relatively large CA3 and small hilus while non-rodent species (including humans and non-human primates) are placed on the opposite side of the spectrum. Hilus and CA3 are also separators within rodents, with a very large CA3 and rather small hilar cell populations separating mole-rats from other rodents that, in turn, are separated from each other by smaller changes in the proportions of CA1 and granule cells. When adult neurogenesis is included, the relatively small populations of young neurons, proliferating cells and hilar neurons become main drivers of taxonomic separation within rodents. The observations provide challenges to the computational modeling of hippocampal function, suggest differences in the organization of hippocampal information streams in rodent and non-rodent species, and support emerging concepts of functional and structural interactions between CA3 and the dentate gyrus.
Collapse
Affiliation(s)
- R Maarten van Dijk
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland; Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH ZurichZürich, Switzerland
| | - Shih-Hui Huang
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland; Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH ZurichZürich, Switzerland
| | - Lutz Slomianka
- Functional Neuroanatomy, Institute of Anatomy, University of Zürich Zurich, Switzerland
| | - Irmgard Amrein
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland
| |
Collapse
|
91
|
Bonfanti L. Adult Neurogenesis 50 Years Later: Limits and Opportunities in Mammals. Front Neurosci 2016; 10:44. [PMID: 26924960 PMCID: PMC4759267 DOI: 10.3389/fnins.2016.00044] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/01/2016] [Indexed: 12/31/2022] Open
Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri OttolenghiOrbassano, Italy; Department of Veterinary Sciences, University of TurinTorino, Italy
| |
Collapse
|
92
|
Dell LA, Patzke N, Spocter MA, Bertelsen MF, Siegel JM, Manger PR. Organization of the sleep-related neural systems in the brain of the river hippopotamus (Hippopotamus amphibius): A most unusual cetartiodactyl species. J Comp Neurol 2016; 524:2036-58. [PMID: 26588600 DOI: 10.1002/cne.23930] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 11/09/2022]
Abstract
This study provides the first systematic analysis of the nuclear organization of the neural systems related to sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the river hippopotamus, one of the closest extant terrestrial relatives of the cetaceans. All nuclei involved in sleep regulation and control found in other mammals, including cetaceans, were present in the river hippopotamus, with no specific nuclei being absent, but novel features of the cholinergic system, including novel nuclei, were present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic, and orexinergic systems and is extended to the γ-aminobutyric acid (GABA)ergic elements of these nuclei. Quantitative analysis reveals that the numbers of pontine cholinergic (259,578) and noradrenergic (127,752) neurons, and hypothalamic orexinergic neurons (68,398) are markedly higher than in other large-brained mammals. These features, along with novel cholinergic nuclei in the intralaminar nuclei of the dorsal thalamus and the ventral tegmental area of the midbrain, as well as a major expansion of the hypothalamic cholinergic nuclei and a large laterodorsal tegmental nucleus of the pons that has both parvocellular and magnocellular cholinergic neurons, indicates an unusual sleep phenomenology for the hippopotamus. Our observations indicate that the hippopotamus is likely to be a bihemispheric sleeper that expresses REM sleep. The novel features of the cholinergic system suggest the presence of an undescribed sleep state in the hippopotamus, as well as the possibility that this animal could, more rapidly than other mammals, switch cortical electroencephalographic activity from one state to another. J. Comp. Neurol. 524:2036-2058, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Leigh-Anne Dell
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, 50312
| | - Mads F Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, 2000, Fredericksberg, Denmark
| | - Jerome M Siegel
- Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Veterans Administration Sepulveda Ambulatory Medical Center, North Hills, California, 91343
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| |
Collapse
|
93
|
Dell LA, Patzke N, Spocter MA, Siegel JM, Manger PR. Organization of the sleep-related neural systems in the brain of the harbour porpoise (Phocoena phocoena). J Comp Neurol 2016; 524:1999-2017. [PMID: 26588354 DOI: 10.1002/cne.23929] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 11/10/2022]
Abstract
The present study provides the first systematic immunohistochemical neuroanatomical investigation of the systems involved in the control and regulation of sleep in an odontocete cetacean, the harbor porpoise (Phocoena phocoena). The odontocete cetaceans show an unusual form of mammalian sleep, with unihemispheric slow waves, suppressed REM sleep, and continuous bodily movement. All the neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals were present in the harbor porpoise, with no specific nuclei being absent, and no novel nuclei being present. This qualitative similarity of nuclear organization relates to the cholinergic, noradrenergic, serotonergic, and orexinergic systems and is extended to the γ-aminobutyric acid (GABA)ergic elements involved with these nuclei. Quantitative analysis of the cholinergic and noradrenergic nuclei of the pontine region revealed that in comparison with other mammals, the numbers of pontine cholinergic (126,776) and noradrenergic (122,878) neurons are markedly higher than in other large-brained bihemispheric sleeping mammals. The diminutive telencephalic commissures (anterior commissure, corpus callosum, and hippocampal commissure) along with an enlarged posterior commissure and supernumerary pontine cholinergic and noradrenergic neurons indicate that the control of unihemispheric slow-wave sleep is likely to be a function of interpontine competition, facilitated through the posterior commissure, in response to unilateral telencephalic input related to the drive for sleep. In addition, an expanded peripheral division of the dorsal raphe nuclear complex appears likely to play a role in the suppression of REM sleep in odontocete cetaceans. Thus, the current study provides several clues to the understanding of the neural control of the unusual sleep phenomenology present in odontocete cetaceans. J. Comp. Neurol. 524:1999-2017, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Leigh-Anne Dell
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, 50312
| | - Jerome M Siegel
- Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Veterans Administration Sepulveda Ambulatory Care Center, North Hills, California, 91343
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, Republic of South Africa
| |
Collapse
|
94
|
Infrasonic and Seismic Communication in the Vertebrates with Special Emphasis on the Afrotheria: An Update and Future Directions. VERTEBRATE SOUND PRODUCTION AND ACOUSTIC COMMUNICATION 2016. [DOI: 10.1007/978-3-319-27721-9_7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
95
|
Abstract
When adult neurogenesis was discovered in the mammalian brain it was often considered an atavism and, even today, many people are convinced that there has been a "phylogenetic reduction" away from lifelong neurogenesis, favoring stability for complex brains. Adult neurogenesis is found throughout the animal kingdom but varies to a large extent. Mammals might have fewer neurogenic zones than, for example, fish, but within their remaining neurogenic zones, the new neurons are highly functional. Especially, humans have very substantial quantities of neurogenesis in their hippocampus. At least for the mammalian dentate gyrus, one can thus argue that there has been evolution toward neurogenesis-based plasticity rather than away from it.
Collapse
Affiliation(s)
- Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden, and CRTD-Center for Regenerative Therapies Dresden at Technische Universität Dresden, 01307 Dresden, Germany
| |
Collapse
|
96
|
Dell LA, Karlsson KA, Patzke N, Spocter MA, Siegel JM, Manger PR. Organization of the sleep-related neural systems in the brain of the minke whale (Balaenoptera acutorostrata). J Comp Neurol 2015; 524:2018-35. [PMID: 26588800 DOI: 10.1002/cne.23931] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 12/12/2022]
Abstract
The current study analyzed the nuclear organization of the neural systems related to the control and regulation of sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the minke whale, a mysticete cetacean. While odontocete cetaceans sleep in an unusual manner, with unihemispheric slow wave sleep (USWS) and suppressed REM sleep, it is unclear whether the mysticete whales show a similar sleep pattern. Previously, we detailed a range of features in the odontocete brain that appear to be related to odontocete-type sleep, and here present our analysis of these features in the minke whale brain. All neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals and the harbor porpoise were present in the minke whale, with no specific nuclei being absent, and no novel nuclei being present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic and orexinergic systems, and the GABAergic elements of these nuclei. Quantitative analysis revealed that the numbers of pontine cholinergic (274,242) and noradrenergic (203,686) neurons, and hypothalamic orexinergic neurons (277,604), are markedly higher than other large-brained bihemispheric sleeping mammals. Small telencephalic commissures (anterior, corpus callosum, and hippocampal), an enlarged posterior commissure, supernumerary pontine cholinergic and noradrenergic cells, and an enlarged peripheral division of the dorsal raphe nuclear complex of the minke whale, all indicate that the suite of neural characteristics thought to be involved in the control of USWS and the suppression of REM in the odontocete cetaceans are present in the minke whale. J. Comp. Neurol. 524:2018-2035, 2016. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Leigh-Anne Dell
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Karl Ae Karlsson
- Biomedical Engineering, Reykjavik University, Reykjavik, Iceland
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, USA
| | - Jerome M Siegel
- Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Sepulveda VAMC, North Hills, California, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| |
Collapse
|
97
|
Parolisi R, Peruffo A, Messina S, Panin M, Montelli S, Giurisato M, Cozzi B, Bonfanti L. Forebrain neuroanatomy of the neonatal and juvenile dolphin (T. truncatus and S. coeruloalba). Front Neuroanat 2015; 9:140. [PMID: 26594155 PMCID: PMC4635206 DOI: 10.3389/fnana.2015.00140] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/16/2015] [Indexed: 12/16/2022] Open
Abstract
Knowledge of dolphin functional neuroanatomy mostly derives from post-mortem studies and non-invasive approaches (i.e., magnetic resonance imaging), due to limitations in experimentation on cetaceans. As a consequence the availability of well-preserved tissues for histology is scarce, and detailed histological analyses are referred mainly to adults. Here we studied the neonatal/juvenile brain in two species of dolphins, the bottlenose dolphin (Tursiops truncatus) and the striped dolphin (Stenella coeruleoalba), with special reference to forebrain regions. We analyzed cell density in subcortical nuclei, white/gray matter ratio, and myelination in selected regions at different anterior–posterior levels of the whole dolphin brain at different ages, to better define forebrain neuroanatomy and the developmental stage of the dolphin brain around birth. The analyses were extended to the periventricular germinal layer and the cerebellum, whose delayed genesis of the granule cell layer is a hallmark of postnatal development in the mammalian nervous system. Our results establish an atlas of the young dolphin forebrain and, on the basis of occurrence/absence of delayed neurogenic layers, confirm the stage of advanced brain maturation in these animals with respect to most terrestrial mammals.
Collapse
Affiliation(s)
- Roberta Parolisi
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy ; Department of Veterinary Sciences, University of Turin Torino, Italy
| | - Antonella Peruffo
- Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy
| | - Silvia Messina
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy
| | - Mattia Panin
- Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy
| | - Stefano Montelli
- Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy
| | - Maristella Giurisato
- Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy ; Department of Veterinary Sciences, University of Turin Torino, Italy
| |
Collapse
|
98
|
Kharlamova AS, Saveliev SV, Protopopov AV, Maseko BC, Bhagwandin A, Manger PR. The mummified brain of a pleistocene woolly mammoth (Mammuthus primigenius) compared with the brain of the extant African elephant (Loxodonta africana). J Comp Neurol 2015; 523:2326-43. [PMID: 26011110 DOI: 10.1002/cne.23817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/14/2015] [Accepted: 05/14/2015] [Indexed: 11/11/2022]
Abstract
This study presents the results of an examination of the mummified brain of a pleistocene woolly mammoth (Mammuthus primigenius) recovered from the Yakutian permafrost in Siberia, Russia. This unique specimen (from 39,440-38,850 years BP) provides the rare opportunity to compare the brain morphology of this extinct species with a related extant species, the African elephant (Loxodonta africana). An anatomical description of the preserved brain of the woolly mammoth is provided, along with a series of quantitative analyses of various brain structures. These descriptions are based on visual inspection of the actual specimen as well as qualitative and quantitative comparison of computed tomography imaging data obtained for the woolly mammoth in comparison with magnetic resonance imaging data from three African elephant brains. In general, the brain of the woolly mammoth specimen examined, estimated to weigh between 4,230 and 4,340 g, showed the typical shape, size, and gross structures observed in extant elephants. Quantitative comparative analyses of various features of the brain, such as the amygdala, corpus callosum, cerebellum, and gyrnecephalic index, all indicate that the brain of the woolly mammoth specimen examined has many similarities with that of modern African elephants. The analysis provided here indicates that a specific brain type representative of the Elephantidae is likely to be a feature of this mammalian family. In addition, the extensive similarities between the woolly mammoth brain and the African elephant brain indicate that the specializations observed in the extant elephant brain are likely to have been present in the woolly mammoth.
Collapse
Affiliation(s)
| | | | - Albert V Protopopov
- Academy of Sciences of the Sakha Republic (Yakutia), Yakutsk, Sakha Republic (Yakutia), 677007, Russia
| | - Busisiwe C Maseko
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, Johannesburg, Republic of South Africa
| |
Collapse
|
99
|
Paredes MF, Sorrells SF, Garcia-Verdugo JM, Alvarez-Buylla A. Brain size and limits to adult neurogenesis. J Comp Neurol 2015; 524:646-64. [PMID: 26417888 DOI: 10.1002/cne.23896] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 08/28/2015] [Accepted: 09/08/2015] [Indexed: 12/31/2022]
Abstract
The walls of the cerebral ventricles in the developing embryo harbor the primary neural stem cells from which most neurons and glia derive. In many vertebrates, neurogenesis continues postnatally and into adulthood in this region. Adult neurogenesis at the ventricle has been most extensively studied in organisms with small brains, such as reptiles, birds, and rodents. In reptiles and birds, these progenitor cells give rise to young neurons that migrate into many regions of the forebrain. Neurogenesis in adult rodents is also relatively widespread along the lateral ventricles, but migration is largely restricted to the rostral migratory stream into the olfactory bulb. Recent work indicates that the wall of the lateral ventricle is highly regionalized, with progenitor cells giving rise to different types of neurons depending on their location. In species with larger brains, young neurons born in these spatially specified domains become dramatically separated from potential final destinations. Here we hypothesize that the increase in size and topographical complexity (e.g., intervening white matter tracts) in larger brains may severely limit the long-term contribution of new neurons born close to, or in, the ventricular wall. We compare the process of adult neuronal birth, migration, and integration across species with different brain sizes, and discuss how early regional specification of progenitor cells may interact with brain size and affect where and when new neurons are added.
Collapse
Affiliation(s)
- Mercedes F Paredes
- Department of Neurological Surgery, University of California, San Francisco, CA, 94143, USA
| | - Shawn F Sorrells
- Department of Neurological Surgery, University of California, San Francisco, CA, 94143, USA.,University of California, San Francisco, CA, 94143, USA
| | - Jose M Garcia-Verdugo
- Laboratory of Comparative Neurobiology, Instituto Cavanilles, Universidad de Valencia, CIBERNED, 46980 Valencia, Spain
| | - Arturo Alvarez-Buylla
- Department of Neurological Surgery and The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, 94143, USA
| |
Collapse
|
100
|
Hevner RF. Evolution of the mammalian dentate gyrus. J Comp Neurol 2015; 524:578-94. [PMID: 26179319 DOI: 10.1002/cne.23851] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/02/2015] [Accepted: 07/06/2015] [Indexed: 01/08/2023]
Abstract
The dentate gyrus (DG), a part of the hippocampal formation, has important functions in learning, memory, and adult neurogenesis. Compared with homologous areas in sauropsids (birds and reptiles), the mammalian DG is larger and exhibits qualitatively different phenotypes: 1) folded (C- or V-shaped) granule neuron layer, concave toward the hilus and delimited by a hippocampal fissure; 2) nonperiventricular adult neurogenesis; and 3) prolonged ontogeny, involving extensive abventricular (basal) migration and proliferation of neural stem and progenitor cells (NSPCs). Although gaps remain, available data indicate that these DG traits are present in all orders of mammals, including monotremes and marsupials. The exception is Cetacea (whales, dolphins, and porpoises), in which DG size, convolution, and adult neurogenesis have undergone evolutionary regression. Parsimony suggests that increased growth and convolution of the DG arose in stem mammals concurrently with nonperiventricular adult hippocampal neurogenesis and basal migration of NSPCs during development. These traits could all result from an evolutionary change that enhanced radial migration of NSPCs out of the periventricular zones, possibly by epithelial-mesenchymal transition, to colonize and maintain nonperiventricular proliferative niches. In turn, increased NSPC migration and clonal expansion might be a consequence of growth in the cortical hem (medial patterning center), which produces morphogens such as Wnt3a, generates Cajal-Retzius neurons, and is regulated by Lhx2. Finally, correlations between DG convolution and neocortical gyrification (or capacity for gyrification) suggest that enhanced abventricular migration and proliferation of NSPCs played a transformative role in growth and folding of neocortex as well as archicortex.
Collapse
Affiliation(s)
- Robert F Hevner
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, 98101
- Department of Neurological Surgery, University of Washington, Seattle, Washington, 98104
| |
Collapse
|