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Çon N, Mercan S, Küçüköner A, Çalişkan N. Adolescent intermittent ethanol use in male rats do not change cerebellar cell numbers but initiate astroglial reaction. Int J Dev Neurosci 2024; 84:177-189. [PMID: 38327108 DOI: 10.1002/jdn.10317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/21/2023] [Accepted: 01/15/2024] [Indexed: 02/09/2024] Open
Abstract
Alcohol consumption during adolescence causes negative structural changes in the cerebellum and can lead to cognitive and motor skill disorders. Unfortunately, the age at which individuals begin drinking alcohol has decreased in recent years, which has drawn attention to the effects of alcohol on neurological changes during preadolescence. In this study, we investigated the effects of adolescent intermittent ethanol (AIE) exposure on the cellular composition of the cerebellum in male rats, particularly when alcohol consumption begins early. The male rats received eight doses of intermittent intraperitoneal injection of 25% (v/v) ethanol (3 g/kg) or saline from postnatal days (PND) 25 to PND 38. In rats, 28-42 days old corresponds to 10-18 years old in humans. Two hours after the last injection, the cells, neurons, and non-neuronal cells in the cerebellum were immunocytochemically labeled and the total numbers of related cells were calculated using the Isotropic Fractionator method. We found that AIE exposure does not change the cell numbers of the cerebellum in the short term, but it does activate astrocytes in the white matter of the cerebellum. These findings suggest that alcohol use during adolescence impairs the innate immune system and negatively affects brain plasticity.
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Affiliation(s)
- Nurhan Çon
- Department of Medical Services and Techniques, Ondokuz Mayıs University, Samsun, Turkey
| | - Sevcan Mercan
- Department of Medical Services and Techniques, Ondokuz Mayıs University, Samsun, Turkey
| | - Asuman Küçüköner
- Department of Medical Services and Techniques, Ondokuz Mayıs University, Samsun, Turkey
| | - Nüket Çalişkan
- Department of Medical Services and Techniques, Ondokuz Mayıs University, Samsun, Turkey
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2
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Castro-Fonseca E, Morais V, da Silva CG, Wollner J, Freitas J, Mello-Neto AF, Oliveira LE, de Oliveira VC, Leite REP, Alho AT, Rodriguez RD, Ferretti-Rebustini REL, Suemoto CK, Jacob-Filho W, Nitrini R, Pasqualucci CA, Grinberg LT, Tovar-Moll F, Lent R. The influence of age and sex on the absolute cell numbers of the human brain cerebral cortex. Cereb Cortex 2023; 33:8654-8666. [PMID: 37106573 PMCID: PMC10321098 DOI: 10.1093/cercor/bhad148] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
The human cerebral cortex is one of the most evolved regions of the brain, responsible for most higher-order neural functions. Since nerve cells (together with synapses) are the processing units underlying cortical physiology and morphology, we studied how the human neocortex is composed regarding the number of cells as a function of sex and age. We used the isotropic fractionator for cell quantification of immunocytochemically labeled nuclei from the cerebral cortex donated by 43 cognitively healthy subjects aged 25-87 years old. In addition to previously reported sexual dimorphism in the medial temporal lobe, we found more neurons in the occipital lobe of men, higher neuronal density in women's frontal lobe, but no sex differences in the number and density of cells in the other lobes and the whole neocortex. On average, the neocortex has ~10.2 billion neurons, 34% in the frontal lobe and the remaining 66% uniformly distributed among the other 3 lobes. Along typical aging, there is a loss of non-neuronal cells in the frontal lobe and the preservation of the number of neurons in the cortex. Our study made possible to determine the different degrees of modulation that sex and age evoke on cortical cellularity.
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Affiliation(s)
- Emily Castro-Fonseca
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- D’Or Institute for Research and Education, Rio de Janeiro, Brazil
| | - Viviane Morais
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Camila G da Silva
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana Wollner
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jaqueline Freitas
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Arthur F Mello-Neto
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz E Oliveira
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vilson C de Oliveira
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renata E P Leite
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Laboratory of Medical Research in Aging (LIM-66), University of São Paulo Medical School, São Paulo, Brazil
| | - Ana T Alho
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
| | - Roberta D Rodriguez
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Department of Pathology, University of São Paulo Medical School, São Paulo, Brazil
| | - Renata E L Ferretti-Rebustini
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Department of Medical Surgical Nursing, University of São Paulo School of Nursing, São Paulo, Brazil
| | - Claudia K Suemoto
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Laboratory of Medical Research in Aging (LIM-66), University of São Paulo Medical School, São Paulo, Brazil
| | - Wilson Jacob-Filho
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Laboratory of Medical Research in Aging (LIM-66), University of São Paulo Medical School, São Paulo, Brazil
| | - Ricardo Nitrini
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Department of Neurology, University of São Paulo Medical School, São Paulo, Brazil
| | - Carlos A Pasqualucci
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Department of Pathology, University of São Paulo Medical School, São Paulo, Brazil
| | - Lea T Grinberg
- Biobank for Aging Studies, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- Department of Pathology, University of São Paulo Medical School, São Paulo, Brazil
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, United States
| | - Fernanda Tovar-Moll
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- D’Or Institute for Research and Education, Rio de Janeiro, Brazil
| | - Roberto Lent
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- D’Or Institute for Research and Education, Rio de Janeiro, Brazil
- National Institute of Translational Neuroscience, Ministry of Science and Technology, São Paulo, Brazil
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3
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de Morais VAC, de Oliveira-Pinto AV, Mello Neto AF, Freitas JS, da Silva MM, Suemoto CK, Leite RP, Grinberg LT, Jacob-Filho W, Pasqualucci C, Nitrini R, Caramelli P, Lent R. Resilience of Neural Cellularity to the Influence of Low Educational Level. Brain Sci 2023; 13:brainsci13010104. [PMID: 36672086 PMCID: PMC9857353 DOI: 10.3390/brainsci13010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/28/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Education is believed to contribute positively to brain structure and function, as well as to cognitive reserve. One of the brain regions most impacted by education is the medial temporal lobe (MTL), a region that houses the hippocampus, which has an important role in learning processes and in consolidation of memories, and is also known to undergo neurogenesis in adulthood. We aimed to investigate the influence of education on the absolute cell numbers of the MTL (comprised by the hippocampal formation, amygdala, and parahippocampal gyrus) of men without cognitive impairment. METHODS The Isotropic Fractionator technique was used to allow the anisotropic brain tissue to be transformed into an isotropic suspension of nuclei, and therefore assess the absolute cell composition of the MTL. We dissected twenty-six brains from men aged 47 to 64 years, with either low or high education. RESULTS A significant difference between groups was observed in brain mass, but not in MTL mass. No significant difference was found between groups in the number of total cells, number of neurons, and number of non-neuronal cells. Regression analysis showed that the total number of cells, number of neurons, and number of non-neuronal cells in MTL were not affected by education. CONCLUSIONS The results indicate a resilience of the absolute cellular composition of the MTL of typical men to low schooling, suggesting that the cellularity of brain regions is not affected by formal education.
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Affiliation(s)
- Viviane A. Carvalho de Morais
- Neuroplasticity Laboratory, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Ana V. de Oliveira-Pinto
- Neuroplasticity Laboratory, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Arthur F. Mello Neto
- Neuroplasticity Laboratory, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Jaqueline S. Freitas
- Neuroplasticity Laboratory, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Magnólia M. da Silva
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Claudia Kimie Suemoto
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Renata P. Leite
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Lea T. Grinberg
- Memory and Aging Center, University of California San Francisco, San Francisco, CA 94158, USA
| | - Wilson Jacob-Filho
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
- Laboratory of Medical Research in Aging (LIM-66), Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Carlos Pasqualucci
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Ricardo Nitrini
- Biobank for Aging Studies, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-903, SP, Brazil
| | - Paulo Caramelli
- Behavioral and Cognitive Neurology Research Group, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte 30130-100, MG, Brazil
| | - Roberto Lent
- Neuroplasticity Laboratory, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
- D’Or Institute of Research and Education, Rio de Janeiro 22281-100, RJ, Brazil
- Correspondence:
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Cunha F, Stingo-Hirmas D, Cardoso RF, Wright D, Henriksen R. Neuronal and non-neuronal scaling across brain regions within an intercross of domestic and wild chickens. Front Neuroanat 2022; 16:1048261. [PMID: 36506870 PMCID: PMC9732670 DOI: 10.3389/fnana.2022.1048261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/11/2022] [Indexed: 11/26/2022] Open
Abstract
The allometric scaling of the brain size and neuron number across species has been extensively studied in recent years. With the exception of primates, parrots, and songbirds, larger brains have more neurons but relatively lower neuronal densities than smaller brains. Conversely, when considering within-population variability, it has been shown that mice with larger brains do not necessarily have more neurons but rather more neurons in the brain reflect higher neuronal density. To what extent this intraspecific allometric scaling pattern of the brain applies to individuals from other species remains to be explored. Here, we investigate the allometric relationships among the sizes of the body, brain, telencephalon, cerebellum, and optic tectum, and the numbers of neurons and non-neuronal cells of the telencephalon, cerebellum, and optic tectum across 66 individuals originated from an intercross between wild and domestic chickens. Our intercross of chickens generates a population with high variation in brain size, making it an excellent model to determine the allometric scaling of the brain within population. Our results show that larger chickens have larger brains with moderately more neurons and non-neuronal cells. Yet, absolute number of neurons and non-neuronal cells correlated strongly and positively with the density of neurons and non-neuronal cells, respectively. As previously shown in mice, this scaling pattern is in stark contrast with what has been found across different species. Our findings suggest that neuronal scaling rules across species are not a simple extension of the neuronal scaling rules that apply within a species, with important implications for the evolutionary developmental origins of brain diversity.
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Wlodkowic D, Bownik A, Leitner C, Stengel D, Braunbeck T. Beyond the behavioural phenotype: Uncovering mechanistic foundations in aquatic eco-neurotoxicology. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154584. [PMID: 35306067 DOI: 10.1016/j.scitotenv.2022.154584] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
During the last decade, there has been an increase in awareness of how anthropogenic pollution can alter behavioural traits of diverse aquatic organisms. Apart from understanding profound ecological implications, alterations in neuro-behavioural indices have emerged as sensitive and physiologically integrative endpoints in chemical risk assessment. Accordingly, behavioural ecotoxicology and broader eco-neurotoxicology are becoming increasingly popular fields of research that span a plethora of fundamental laboratory experimentations as well as applied field-based studies. Despite mounting interest in aquatic behavioural ecotoxicology studies, there is, however, a considerable paucity in deciphering the mechanistic foundations underlying behavioural alterations upon exposure to pollutants. The behavioural phenotype is indeed the highest-level integrative neurobiological phenomenon, but at its core lie myriads of intertwined biochemical, cellular, and physiological processes. Therefore, the mechanisms that underlie changes in behavioural phenotypes can stem among others from dysregulation of neurotransmitter pathways, electrical signalling, and cell death of discrete cell populations in the central and peripheral nervous systems. They can, however, also be a result of toxicity to sensory organs and even metabolic dysfunctions. In this critical review, we outline why behavioural phenotyping should be the starting point that leads to actual discovery of fundamental mechanisms underlying actions of neurotoxic and neuromodulating contaminants. We highlight potential applications of the currently existing and emerging neurobiology and neurophysiology analytical strategies that should be embraced and more broadly adopted in behavioural ecotoxicology. Such strategies can provide new mechanistic discoveries instead of only observing the end sum phenotypic effects.
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Affiliation(s)
- Donald Wlodkowic
- The Neurotox Laboratory, School of Science, RMIT University, Melbourne, Australia.
| | - Adam Bownik
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences, Lublin, Poland
| | - Carola Leitner
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Daniel Stengel
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
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6
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Raji JI, Potter CJ. The number of neurons in Drosophila and mosquito brains. PLoS One 2021; 16:e0250381. [PMID: 33989293 PMCID: PMC8121336 DOI: 10.1371/journal.pone.0250381] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/03/2021] [Indexed: 01/08/2023] Open
Abstract
Various insect species serve as valuable model systems for investigating the cellular and molecular mechanisms by which a brain controls sophisticated behaviors. In particular, the nervous system of Drosophila melanogaster has been extensively studied, yet experiments aimed at determining the number of neurons in the Drosophila brain are surprisingly lacking. Using isotropic fractionator coupled with immunohistochemistry, we counted the total number of neuronal and non-neuronal cells in the whole brain, central brain, and optic lobe of Drosophila melanogaster. For comparison, we also counted neuronal populations in three divergent mosquito species: Aedes aegypti, Anopheles coluzzii and Culex quinquefasciatus. The average number of neurons in a whole adult brain was determined to be 199,380 ±3,400 cells in D. melanogaster, 217,910 ±6,180 cells in Ae. aegypti, 223,020 ± 4,650 cells in An. coluzzii and 225,911±7,220 cells in C. quinquefasciatus. The mean neuronal cell count in the central brain vs. optic lobes for D. melanogaster (101,140 ±3,650 vs. 107,270 ± 2,720), Ae. aegypti (109,140 ± 3,550 vs. 112,000 ± 4,280), An. coluzzii (105,130 ± 3,670 vs. 107,140 ± 3,090), and C. quinquefasciatus (108,530 ±7,990 vs. 110,670 ± 3,950) was also estimated. Each insect brain was comprised of 89% ± 2% neurons out of its total cell population. Isotropic fractionation analyses did not identify obvious sexual dimorphism in the neuronal and non-neuronal cell population of these insects. Our study provides experimental evidence for the total number of neurons in Drosophila and mosquito brains.
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Affiliation(s)
- Joshua I. Raji
- The Solomon H. Snyder Department of Neuroscience, The Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Christopher J. Potter
- The Solomon H. Snyder Department of Neuroscience, The Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail:
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Aicardi S, Amaroli A, Gallus L, Ferrando S. Effects of nasal parasite species in the small-spotted catshark Scyliorhinus canicula (Scyliorhinidae; Carcharhiniformes). JOURNAL OF VERTEBRATE BIOLOGY 2020. [DOI: 10.25225/jvb.20052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Stefano Aicardi
- Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy; e-mail: ; ;
| | - Andrea Amaroli
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy; e-mail:
| | - Lorenzo Gallus
- Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy; e-mail: ; ;
| | - Sara Ferrando
- Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy; e-mail: ; ;
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8
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Neves K, Guercio GD, Anjos-Travassos Y, Costa S, Perozzo A, Montezuma K, Herculano-Houzel S, Panizzutti R. The relationship between the number of neurons and behavioral performance in Swiss mice. Neurosci Lett 2020; 735:135202. [PMID: 32599318 DOI: 10.1016/j.neulet.2020.135202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/21/2020] [Indexed: 10/24/2022]
Abstract
Neuronal number varies by several orders of magnitude across species, and has been proposed to predict cognitive capability across species. Remarkably, numbers of neurons vary across individual mice by a factor of 2 or more. We directly addressed the question of whether there is a relationship between performance in behavioral tests and the number of neurons in functionally relevant structures in the mouse brain. Naïve Swiss mice went through a battery of behavioral tasks designed to measure cognitive, motor and olfactory skills. We estimated the number of neurons in different brain regions (cerebral cortex, hippocampus, olfactory bulb, cerebellum and remaining areas) and crossed the two datasets to test the a priori hypothesis of correlation between cognitive abilities and numbers of neurons. Surprisingly, performance in the behavioral tasks did not correlate strongly with number of neurons in any of the brain regions studied. Our results show that whereas neuronal number is a predictor of cognitive skills across species, it is not a good predictor of cognitive, sensory or motor ability across individuals within a species, which suggests that other factors are more relevant for explaining cognitive differences between individuals of the same species.
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Affiliation(s)
- Kleber Neves
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil; Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil.
| | - Gerson Duarte Guercio
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil; Department of Psychiatry, University of Minnesota, 2312 S 6th St., Minneapolis, MN, United States.
| | - Yuri Anjos-Travassos
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil
| | - Stella Costa
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil
| | - Ananda Perozzo
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil
| | - Karine Montezuma
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil
| | - Suzana Herculano-Houzel
- Department of Psychology, Department of Biological Sciences, Vanderbilt Brain Institute, Vanderbilt University, United States
| | - Rogério Panizzutti
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil; Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro, Brazil
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Aicardi S, Amaroli A, Gallus L, Di Blasi D, Ghigliotti L, Betti F, Vacchi M, Ferrando S. Quantification of neurons in the olfactory bulb of the catsharks Scyliorhinus canicula (Linnaeus, 1758) and Galeus melastomus (Rafinesque, 1810). ZOOLOGY 2020; 141:125796. [PMID: 32464514 DOI: 10.1016/j.zool.2020.125796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 11/27/2022]
Abstract
In vertebrates, the olfactory bulb (OB) is the zone of the brain devoted to receiving the olfactory stimuli. The size of the OB relative to the size of the brain has been positively correlated to a good olfactory capability but, recently, this correlation was questioned after new investigation techniques were developed. Among them, the isotropic fractionator allows to estimate the number of neurons and non-neurons in a given portion of nervous tissue. To date, this technique has been applied in a number of species; in particular the OB was separately analyzed in numerous mammals and in a single crocodile species. Thus, a quantitative description of the OB's cells is available for a small portion of vertebrates. Main aim of this work was to apply isotropic fractionator to investigate the olfactory capability of elasmobranch fishes, whose traditional concept of outstanding olfaction has recently been scaled down by anatomical and physiological studies. For this purpose, the OB of two elasmobranch species, Galeus melastomus and Scyliorhinus canicula, was studied leading to the determination of the number of neurons vs non-neurons in the OB of the specimens. In addition, the obtained cell quantification was related to the olfactory epithelium surface area to obtain a new parameter that encapsulates both information on the peripheral olfactory organ and the OB. The analyzed species resulted in an overall similar quantitative organization of the peripheral olfactory system; slight differences were detected possibly reflecting different environment preference and feeding strategy. Moreover, the non-neurons/neurons ratio of these species, compared to those available in the literature, seems to place elasmobranch fishes among the vertebrate species in which olfaction plays an important role.
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Affiliation(s)
- Stefano Aicardi
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa, 26, 16132, Genoa, Italy
| | - Andrea Amaroli
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Largo Rosanna Benzi, 8, 16132, Genoa, Italy; Department of Orthopedic Dentistry, Institute of Dentistry, I. M. Sechenov First Moscow State Medical University, Bol'shaya Pirogovskaya Ulitsa, 19с1, Moscow, 119146, Russia
| | - Lorenzo Gallus
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa, 26, 16132, Genoa, Italy
| | - Davide Di Blasi
- Institute for the Study of Anthropogenic Impacts and Sustainability in the Marine Environment (IAS), National Research Council (CNR), Via De Marini, 6, 16149, Genoa, Italy
| | - Laura Ghigliotti
- Institute for the Study of Anthropogenic Impacts and Sustainability in the Marine Environment (IAS), National Research Council (CNR), Via De Marini, 6, 16149, Genoa, Italy
| | - Federico Betti
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa, 26, 16132, Genoa, Italy
| | - Marino Vacchi
- Institute for the Study of Anthropogenic Impacts and Sustainability in the Marine Environment (IAS), National Research Council (CNR), Via De Marini, 6, 16149, Genoa, Italy
| | - Sara Ferrando
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa, 26, 16132, Genoa, Italy.
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Němec P, Osten P. The evolution of brain structure captured in stereotyped cell count and cell type distributions. Curr Opin Neurobiol 2020; 60:176-183. [PMID: 31945723 PMCID: PMC7191610 DOI: 10.1016/j.conb.2019.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/13/2022]
Abstract
The stereotyped features of brain structure, such as the distribution, morphology and connectivity of neuronal cell types across brain areas, are those most likely to explain the remarkable capacity of the brain to process information and govern behaviors. Recent advances in anatomical methods, including the simple but versatile isotropic fractionator and several whole-brain labeling, clearing and microscopy methods, have opened the door to an exciting new era in comparative brain anatomy, one that has the potential to transform our understanding of the brain structure-function relationship by representing the evolution of brain complexity in quantitative anatomical features shared across species and species-specific or clade-specific. Here we discuss these methods and their application to mapping brain cell count and cell type distributions-two particularly powerful neural correlates of vertebrate cognitive and behavioral capabilities.
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Affiliation(s)
- Pavel Němec
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague, Czech Republic.
| | - Pavel Osten
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11743, USA.
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11
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Early exercise induces long-lasting morphological changes in cortical and hippocampal neurons throughout of a sedentary period of rats. Sci Rep 2019; 9:13684. [PMID: 31548605 PMCID: PMC6757043 DOI: 10.1038/s41598-019-50218-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 09/03/2019] [Indexed: 01/10/2023] Open
Abstract
Life experiences at early ages, such as physical activity in childhood and adolescence, can result in long-lasting brain effects able to reduce future risk of brain disorders and to enhance lifelong brain functions. However, how early physical exercise promotes these effects remains unclear. A possible hypothesis is that physical exercise increases the expression of neurotrophic factors and stimulates neuronal growth, resulting in a neural reserve to be used at later ages. Basing our study on this hypothesis, we evaluated the absolute number and morphology of neuronal cells, as well as the expression of growth, proliferation and survival proteins (BDNF, Akt, mTOR, p70S6K, ERK and CREB) in the cerebral cortex and hippocampal formation throughout of a sedentary period of rats who were physically active during youth. To do this, male Wistar rats were submitted to an aerobic exercise protocol from the 21st to the 60th postnatal days (P21–P60), and evaluated at 0 (P60), 30 (P90) and 60 (P120) days after the last exercise session. Results showed that juvenile exercise increased, and maintained elevated, the number of cortical and hippocampal neuronal cells and dendritic arborization, when evaluated at the above post-exercise ages. Hippocampal BDNF levels and cortical mTOR expression were found to be increased at P60, but were restored to control levels at P90 and P120. Overall, these findings indicate that, despite the short-term effects on growth and survival proteins, early exercise induces long-lasting morphological changes in cortical and hippocampal neurons even during a sedentary period of rats.
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