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Gobbo DR, Pereira LDS, Ferreira JGP, de Castro Horta-Junior JA, Bittencourt JC, Sá SI. Effects of ovariectomy on the inputs from the medial nucleus of the amygdala to the ventromedial nucleus of the hypothalamus in young adult rats. Neurosci Lett 2021; 746:135657. [PMID: 33482312 DOI: 10.1016/j.neulet.2021.135657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/12/2021] [Indexed: 10/22/2022]
Abstract
During puberty, sexual hormones induce crucial changes in neural circuit organization, leading to significant sexual dimorphism in adult behaviours. The ventrolateral division of the ventromedial nucleus of the hypothalamus (VMHvl) is the major neural site controlling the receptive component of female sexual behaviour, which is dependent on ovarian hormones. The inputs to the VMHvl, originating from the medial nucleus of the amygdala (MeA), transmit essential information to trigger such behaviour. In this study, we investigated the projection pattern of the MeA to the VMHvl in ovariectomized rats at early puberty. Six-week-old Sprague-Dawley rats were ovariectomized (OVX) and, upon reaching 90 days of age, were subjected to iontophoretic injections of the neuronal anterograde tracer Phaseolus vulgaris leucoagglutinin into the MeA. Projections from the MeA to the VMHvl and to other structures included in the neural circuit responsible for female sexual behaviour were analysed in the Control and OVX groups. The results of the semi-quantitative analysis showed that peripubertal ovariectomy reduced the density of intra-amygdalar fibres. The stereological estimates, however, failed to find changes in the organization of the terminal fields of nerve fibres from the MeA to the VMHvl in the adult. The present data show that ovariectomized rats during the peripubertal phase did not undergo significant changes in MeA fibres reaching the VMHvl; however, they suggest a possible effect of ovariectomy on MeA connectivity under amygdalar subnuclei.
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Affiliation(s)
- Denise Ribeiro Gobbo
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Laboratorio de Neuroanatomia Quimica, Departamento de Anatomia, Sao Paulo, SP, Brazil
| | - Lais da Silva Pereira
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Laboratorio de Neuroanatomia Quimica, Departamento de Anatomia, Sao Paulo, SP, Brazil
| | - Jozélia Gomes Pacheco Ferreira
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Laboratorio de Neuroanatomia Quimica, Departamento de Anatomia, Sao Paulo, SP, Brazil
| | | | - Jackson Cioni Bittencourt
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Laboratorio de Neuroanatomia Quimica, Departamento de Anatomia, Sao Paulo, SP, Brazil; Universidade de Sao Paulo, Instituto de Psicologia, Nucleo de Neurociências e Comportamento, São Paulo, SP, Brazil.
| | - Susana Isabel Sá
- Department of Biomedicine, Unit of Anatomy, Faculty of Medicine, University of Porto, Porto, Portugal; CINTESIS, Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.
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Dalpian F, Rasia-Filho AA, Calcagnotto ME. Sexual dimorphism, estrous cycle and laterality determine the intrinsic and synaptic properties of medial amygdala neurons in rat. J Cell Sci 2019; 132:jcs.227793. [PMID: 30967401 DOI: 10.1242/jcs.227793] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 03/29/2019] [Indexed: 01/06/2023] Open
Abstract
The posterodorsal medial amygdala (MePD) is a sex steroid-sensitive area that modulates different social behavior by relaying chemosensorial information to hypothalamic nuclei. However, little is known about MePD cell type diversity and functional connectivity. Here, we have characterized neurons and synaptic inputs in the right and left MePD of adult male and cycling female (in diestrus, proestrus or estrus) rats. Based on their electrophysiological properties and morphology, we found two coexisting subpopulations of spiny neurons that are sexually dimorphic. They were classified as Class I (predominantly bitufted-shaped neurons showing irregular spikes with frequency adaptation) or Class II (predominantly stellate-shaped neurons showing full spike frequency adaptation). Furthermore, excitatory and inhibitory inputs onto MePD cells were modulated by sex, estrous cycle and hemispheric lateralization. In the left MePD, there was an overall increase in the excitatory input to neurons of males compared to cycling females. However, in proestrus, the MePD neurons received mainly inhibitory inputs. Our findings indicate the existence of hemispheric lateralization, estrous cycle and sexual dimorphism influences at cellular and synaptic levels in the adult rat MePD.
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Affiliation(s)
- Francine Dalpian
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90170-050, Brazil
| | - Alberto A Rasia-Filho
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90170-050, Brazil.,Department of Basic Sciences/Physiology, Federal University of Health Sciences, Porto Alegre, RS 90170-050, Brazil
| | - Maria Elisa Calcagnotto
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90170-050, Brazil .,Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil
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Yang L, Dun W, Li K, Yang J, Wang K, Liu H, Liu J, Zhang M. Altered amygdalar volume and functional connectivity in primary dysmenorrhoea during the menstrual cycle. Eur J Pain 2019; 23:994-1005. [PMID: 30664322 DOI: 10.1002/ejp.1368] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 11/27/2018] [Accepted: 01/17/2019] [Indexed: 01/25/2023]
Affiliation(s)
- Ling Yang
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
- Radiology Department; Chong Qing General Hospital; Chong Qing China
| | - Wanghuan Dun
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
| | - Kang Li
- Radiology Department; Chong Qing General Hospital; Chong Qing China
| | - Jing Yang
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
| | - Ke Wang
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
| | - Hongjuan Liu
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
| | - Jixin Liu
- Center for Brain Imaging; School of Life Science and Technology; Xidian University; Xi'an China
| | - Ming Zhang
- Department of Medical Imaging; First Affiliated Hospital of Xi'an Jiaotong University; Xi'an China
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Hirsch MM, Brusco J, Vaccaro T, Margis R, Moreira JE, Gottfried C, Rasia-Filho AA. Sex Differences and Estrous Cycle Changes in Synaptic Plasticity-related microRNA in the Rat Medial Amygdala. Neuroscience 2018; 379:405-414. [DOI: 10.1016/j.neuroscience.2018.03.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 02/20/2018] [Accepted: 03/21/2018] [Indexed: 01/05/2023]
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5
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Deng D, Pang Y, Duan G, Liu H, Liao H, Liu P, Liu Y, Li S, Chen W, Wen D, Xuan C, Li M. Larger volume and different functional connectivity of the amygdala in women with premenstrual syndrome. Eur Radiol 2017; 28:1900-1908. [PMID: 29260367 DOI: 10.1007/s00330-017-5206-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 11/14/2017] [Accepted: 11/22/2017] [Indexed: 01/15/2023]
Abstract
OBJECTIVES To assess structural and functional changes of the amygdala due to premenstrual syndrome (PMS) using magnetic resonance imaging (MRI). METHODS Twenty PMS patients and 21 healthy control (HC) subjects underwent a 6-min resting-state fMRI scan during the luteal phase as well as scanning high-resolution T1-weighted images. Subcortical amygdala-related volume and functional connectivity (FC) were estimated between the two groups. Each subject completed a daily record of severity of problems (DRSP) to measure the severity of clinical symptoms. RESULTS Greater bilateral amygdalae volumes were found in PMS patients compared with HC subjects, and PMS patients had increased FC between the amygdala and certain regions of the frontal cortex (e.g. medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), right precentral gyrus), the right temporal pole and the insula, as well as decreased FC between the bilateral amygdalae and the right orbitofrontal cortex and right hippocampus. The strength of FC between the right amygdala and right precentral gyrus, left ACC and left mPFC were significantly and positively correlated with DRSP scores in PMS patients. CONCLUSIONS Our findings may improve our understanding of the neural mechanisms involved in PMS. KEY POINTS • Functional and structural MRI used to explore amygdala in PMS patients. • Aberrant amygdala structural and functional connectivity were found in PMS patients. • Amygdala strength FC was positively correlated with individual clinical symptom scores.
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Affiliation(s)
- Demao Deng
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China.
| | - Yong Pang
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Gaoxiong Duan
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Huimei Liu
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Hai Liao
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Peng Liu
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Yanfei Liu
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Shasha Li
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Wenfu Chen
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Danhong Wen
- Department of Teaching, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Chunmei Xuan
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
| | - Min Li
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, Guangxi, 530023, China
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Santos AS, Almeida W, Popik B, Sbardelotto BM, Torrejais MM, Souza MA, Centenaro LA. Characterization of a cerebral palsy‐like model in rats: Analysis of gait pattern and of brain and spinal cord motor areas. Int J Dev Neurosci 2017; 60:48-55. [DOI: 10.1016/j.ijdevneu.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/29/2017] [Accepted: 04/29/2017] [Indexed: 12/23/2022] Open
Affiliation(s)
- Adriana Souza Santos
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Wellington Almeida
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Bruno Popik
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Bruno Marques Sbardelotto
- Laboratório de Morfologia Experimental, Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Márcia Miranda Torrejais
- Laboratório de Morfologia Experimental, Programa de Pós‐Graduação em Biociências e Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Marcelo Alves Souza
- Universidade Federal do Paraná, Rua General Rondon2195, ToledoParanáCEP: 85902‐090Brazil
| | - Lígia Aline Centenaro
- Laboratório de Morfologia Experimental, Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
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7
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Zancan M, Dall'Oglio A, Quagliotto E, Rasia‐Filho AA. Castration alters the number and structure of dendritic spines in the male posterodorsal medial amygdala. Eur J Neurosci 2016; 45:572-580. [DOI: 10.1111/ejn.13460] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/22/2016] [Accepted: 10/31/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Mariana Zancan
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
- Graduation Program in Neuroscience Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Aline Dall'Oglio
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
| | - Edson Quagliotto
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
| | - Alberto A. Rasia‐Filho
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
- Graduation Program in Neuroscience Federal University of Rio Grande do Sul Porto Alegre Brazil
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8
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Skeletal muscle electrical stimulation improves baroreflex sensitivity and heart rate variability in heart failure rats. Auton Neurosci 2015; 193:92-6. [DOI: 10.1016/j.autneu.2015.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/19/2015] [Accepted: 08/22/2015] [Indexed: 11/20/2022]
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9
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Zancan M, Dall'Oglio A, Sarzenski TM, Maher MI, Garcia-Segura LM, Rasia-Filho AA. Glial and axonal perikaryal coverage and somatic spines in the posterodorsal medial amygdala of male and cycling female rats. J Comp Neurol 2015; 523:2127-37. [DOI: 10.1002/cne.23782] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Mariana Zancan
- DCBS-Physiology, Federal University of Health Sciences; Porto Alegre, Rio Grande do Sul 90050-110 Brazil
| | - Aline Dall'Oglio
- DCBS-Physiology, Federal University of Health Sciences; Porto Alegre, Rio Grande do Sul 90050-110 Brazil
| | - Taís Malysz Sarzenski
- ICBS-Anatomy, Federal University of Rio Grande do Sul; Porto Alegre, Rio Grande do Sul 90050-110 Brazil
| | - Martin Ian Maher
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC); 28002 Madrid Spain
| | | | - Alberto A. Rasia-Filho
- DCBS-Physiology, Federal University of Health Sciences; Porto Alegre, Rio Grande do Sul 90050-110 Brazil
- Graduation Program in Neurosciences, Federal University of Rio Grande do Sul; Porto Alegre, Rio Grande do Sul 90050-110 Brazil
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10
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Brusco J, Merlo S, Ikeda ÉT, Petralia RS, Kachar B, Rasia-Filho AA, Moreira JE. Inhibitory and multisynaptic spines, and hemispherical synaptic specialization in the posterodorsal medial amygdala of male and female rats. J Comp Neurol 2015; 522:2075-88. [PMID: 24318545 DOI: 10.1002/cne.23518] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/26/2013] [Accepted: 12/03/2013] [Indexed: 12/23/2022]
Abstract
The density of dendritic spines is sexually dimorphic and variable throughout the female estrous cycle in the rat posterodorsal medial amygdala (MePD), a relevant area for the modulation of reproductive behavior in rats. The local synaptic activity differs between hemispheres in prepubertal animals. Here we used serial section transmission electron microscopy to produce 3D reconstructions of dendritic shafts and spines to characterize synaptic contacts on MePD neurons of both hemispheres in adult males and in females along the estrous cycle. Pleomorphic spines and nonsynaptic filopodia occur in the MePD. On average, 8.6% of dendritic spines received inputs from symmetric gamma-aminobutyric acid (GABA)-immunoreactive terminals, whereas 3.6% received two synaptic contacts on the spine head, neck, or base. Presynaptic terminals in female right MePD had a higher density of synaptic vesicles and docked vesicles than the left MePD, suggesting a higher rate of synaptic vesicle release in the right MePD of female rats. In contrast, males did not show laterality in any of those parameters. The proportion of putative inhibitory synapses on dendritic shafts in the right MePD of females in proestrus was higher than in the left MePD, and higher than in the right MePD in males, or in females in diestrus or estrus. This work shows synaptic laterality depending on sex and estrous cycle phase in mature MePD neurons. Most likely, sexual hormone effects are lateralized in this brain region, leading to higher synaptic activity in the right than in the left hemisphere of females, mediating timely neuroendocrine and social/reproductive behavior.
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Affiliation(s)
- Janaina Brusco
- Department of Neuroscience and Behavior, University of São Paulo, School of Medicine at Ribeirão Preto, Ribeirão Preto, SP, 14049-900, Brazil; National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
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11
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Kumar V, Vasudevan A, Soh LJT, Le Min C, Vyas A, Zewail-Foote M, Guarraci FA. Sexual attractiveness in male rats is associated with greater concentration of major urinary proteins. Biol Reprod 2014; 91:150. [PMID: 25359898 DOI: 10.1095/biolreprod.114.117903] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Female rats show a distinct attraction for males. This attraction remains consistent without the necessity for the physical presence of the male. However, the identity of the olfactory cues contributing to attraction in rats remains unknown. Rat urine contains copious amounts of major urinary proteins (MUPs). Here, we investigated the hypothesis that MUPs mediate sexual attractiveness in rats. We first demonstrated that a member of a male dyad receiving greater copulatory opportunities in competitive mate choice tests excrete greater amounts of MUPs. Furthermore, the amount of male MUPs positively correlated with both copulatory opportunities received and female exploration of the urine. Using females and a two-choice olfactory attraction test, we demonstrated that urinary fractions containing MUPs were sufficient to induce attraction and that male MUPs activated neurons in the posterodorsal medial amygdala in female rats. Taken together, these results suggest that olfactory cues associated with MUPs act as an attractant to female rats in estrus.
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Affiliation(s)
- Vineet Kumar
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Anand Vasudevan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Linda Jing Ting Soh
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Choo Le Min
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Ajai Vyas
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Maha Zewail-Foote
- Department of Chemistry and Biochemistry, Southwestern University, Georgetown, Texas
| | - Fay A Guarraci
- Department of Psychology, Southwestern University, Georgetown, Texas
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12
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Farrell MR, Sengelaub DR, Wellman CL. Sex differences and chronic stress effects on the neural circuitry underlying fear conditioning and extinction. Physiol Behav 2013; 122:208-15. [PMID: 23624153 PMCID: PMC3812406 DOI: 10.1016/j.physbeh.2013.04.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 04/11/2013] [Accepted: 04/16/2013] [Indexed: 11/20/2022]
Abstract
There are sex differences in the rates of many stress-sensitive psychological disorders such as posttraumatic stress disorder (PTSD). As medial prefrontal cortex and amygdala are implicated in many of these disorders, understanding differential stress effects in these regions may shed light on the mechanisms underlying sex-dependent expression of disorders like depression and anxiety. Prefrontal cortex and amygdala are key regions in the neural circuitry underlying fear conditioning and extinction, which thus has emerged as a useful model of stress influences on the neural circuitry underlying regulation of emotional behavior. This review outlines the current literature on sex differences and stress effects on dendritic morphology within medial prefrontal cortex and basolateral amygdala. Such structural differences and/or alterations can have important effects on fear conditioning and extinction, behaviors that are mediated by the basolateral amygdala and prefrontal cortex, respectively. Given the importance of extinction-based exposure therapy as a treatment for anxiety disorders such as PTSD, understanding the neural mechanisms by which stress differentially influences fear learning and extinction in males and females is an important goal for developing sex-appropriate interventions for stress-related disorders.
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Affiliation(s)
- Mollee R Farrell
- Department of Psychological & Brain Sciences, Program in Neuroscience, and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, United States.
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13
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Ninan I. Synaptic regulation of affective behaviors; role of BDNF. Neuropharmacology 2013; 76 Pt C:684-95. [PMID: 23747574 DOI: 10.1016/j.neuropharm.2013.04.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 03/31/2013] [Accepted: 04/02/2013] [Indexed: 12/23/2022]
Abstract
Brain derived neurotrophic factor (BDNF), a neurotrophin essential for nervous system development and synaptic plasticity, has been found to have a significant influence on affective behaviors. The notion that an impairment in BDNF signaling might be involved in affective disorders is originated primarily from the opposing effects of antidepressants and stress on BDNF signaling. Antidepressants enhance BDNF signaling and synaptic plasticity. On the other hand, negative environmental factors such as severe stress suppress BDNF signaling, impair synaptic activity and increase susceptibility to affective disorders. Postmortem studies provided strong support for decreased BDNF signaling in depressive disorders. Remarkably, studies in humans with a single nucleotide polymorphism in the BDNF gene, the BDNF Val66Met which affects regulated release of BDNF, showed profound deficits in hippocampal and prefrontal cortical (PFC) plasticity and cognitive behaviors. BDNF regulates synaptic mechanisms responsible for various cognitive processes including attenuation of aversive memories, a key process in the regulation of affective behaviors. The unique role of BDNF in cognitive and affective behaviors suggests that cognitive deficits due to altered BDNF signaling might underlie affective disorders. Understanding how BDNF modulates synapses in neural circuits relevant to affective behaviors, particularly the medial prefrontal cortical (mPFC)-hippocampus-amygdala pathway, and its interaction with development, sex, and environmental risk factors might shed light on potential therapeutic targets for affective disorders. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.
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Affiliation(s)
- Ipe Ninan
- Department of Psychiatry, NYU School of Medicine, SKI 5-3, 540 1st Ave, NY 10016, United States.
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14
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Dall'Oglio A, Xavier LL, Hilbig A, Ferme D, Moreira JE, Achaval M, Rasia-Filho AA. Cellular components of the human medial amygdaloid nucleus. J Comp Neurol 2013; 521:589-611. [PMID: 22806548 DOI: 10.1002/cne.23192] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 04/22/2012] [Accepted: 07/10/2012] [Indexed: 12/24/2022]
Abstract
The medial nucleus (Me) is a superficial component of the amygdaloid complex. Here we assessed the density and morphology of the neurons and glial cells, the glial fibrillary acidic protein (GFAP) immunoreactivity, and the ultrastructure of the synaptic sites in the human Me. The optical fractionator method was applied. The Me presented an estimated mean neuronal density of 1.53 × 10⁵ neurons/mm³ (greater in the left hemisphere), more glia (72% of all cells) than neurons, and a nonneuronal:neuronal ratio of 2.7. Golgi-impregnated neurons had round or ovoid, fusiform, angular, and polygonal cell bodies (10-30 μm in diameter). The length of the dendrites varied, and pleomorphic spines were found in sparsely spiny or densely spiny cells (1.5-5.2 spines/dendritic μm). The axons in the Me neuropil were fine or coarsely beaded, and fibers showed simple or notably complex collateral terminations. The protoplasmic astrocytes were either isolated or formed small clusters and showed GFAP-immunoreactive cell bodies and multiple branches. Furthermore, we identified both asymmetrical (with various small, clear, round, electron-lucent vesicles and, occasionally, large, dense-core vesicles) and symmetrical (with small, flattened vesicles) axodendritic contacts, also including multisynaptic spines. The astrocytes surround and may compose tripartite or tetrapartite synapses, the latter including the extracellular matrix between the pre- and the postsynaptic elements. Interestingly, the terminal axons exhibited a glomerular-like structure with various asymmetrical contacts. These new morphological data on the cellular population and synaptic complexity of the human Me can contribute to our knowledge of its role in health and pathological conditions.
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Affiliation(s)
- Aline Dall'Oglio
- Neuroscience Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre 90170-050-RS, Brazil
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15
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Matsuda KI, Yanagisawa M, Sano K, Ochiai I, Musatov S, Okoshi K, Tsukahara S, Ogawa S, Kawata M. Visualisation and characterisation of oestrogen receptor α-positive neurons expressing green fluorescent protein under the control of the oestrogen receptor α promoter. Eur J Neurosci 2013; 38:2242-9. [PMID: 23601009 DOI: 10.1111/ejn.12227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 03/21/2013] [Indexed: 12/20/2022]
Abstract
Oestrogen receptor (ER)α plays important roles in the development and function of various neuronal systems through activation by its ligands, oestrogens. To visualise ERα-positive neurons, we generated transgenic (tg) mice expressing green fluorescent protein (GFP) under the control of the ERα promoter. In three independent tg lines, GFP-positive neurons were observed in areas previously reported to express ERα mRNA, including the lateral septum, bed nucleus of the stria terminalis, medial preoptic nucleus (MPO), hypothalamus, and amygdala. In these areas, GFP signals mostly overlapped with ERα immunoreactivity. GFP fluorescence was seen in neurites and cell bodies of neurons. In addition, the network and detailed structure of neurites were visible in dissociated and slice cultures of hypothalamic neurons. We examined the effect of oestrogen deprivation by ovariectomy on the structure of the GFP-positive neurons. The area of ERα-positive cell bodies in the bed nucleus of the stria terminalis and MPO was measured by capturing the GFP signal and was found to be significantly smaller in ovariectomy mice than in control mice. When neurons in the MPO were infected with an adeno-associated virus that expressed small hairpin RNA targeting the ERα gene, an apparent induction of GFP was observed in this area, suggesting a negative feedback mechanism in which ERα controls expression of the ERα gene itself. Thus, the ERα promoter-GFP tg mice will be useful to analyse the development and plastic changes of the structure of ERα-expressing neurons and oestrogen and its receptor-mediated neuronal responses.
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Affiliation(s)
- Ken Ichi Matsuda
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, 465 Kawaramachi Hirokoji, Kamigyoku, Kyoto 602-8566, Japan.
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Centenaro LA, da Cunha Jaeger M, Ilha J, de Souza MA, Balbinot LF, do Nascimento PS, Marcuzzo S, Achaval M. Implications of olfactory lamina propria transplantation on hyperreflexia and myelinated fiber regeneration in rats with complete spinal cord transection. Neurochem Res 2012. [PMID: 23179588 DOI: 10.1007/s11064-012-0928-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Transplantation with olfactory ensheathing cells (OECs) has been adopted after several models of spinal cord injury (SCI) with the purpose of creating a favorable environment for the re-growth of injured axons. However, a consensus on the efficacy of this cellular transplantation has yet to be reached. In order to explore alternative parameters that could demonstrate the possible restorative properties of such grafts, the present study investigated the effects of olfactory lamina propria (OLP) transplantation on hyperreflexia and myelinated fiber regeneration in adult rats with complete spinal cord transection. The efficacy of OLP (graft containing OECs) and respiratory lamina propria (RLP, graft without OECs) was tested at different post-injury times (acutely, 2- and 4-week delayed), to establish the optimum period for transplantation. In the therapeutic windows used, OLP and RLP grafts produced no considerable improvements in withdrawal reflex responses or on the low-frequency dependent depression of H-reflex. Both lamina propria grafts produced comparable results for the myelinated fiber density and for the estimated total number of myelinated fibers at the lesion site, indicating that the delayed transplantation approach does not seem to limit the regenerative effects. However, animals transplanted with OLP 2 or 4 weeks after injury exhibit smaller myelin sheath thickness and myelinated fiber area and diameter at the lesion site compared to their respective RLP groups. Despite the ongoing clinical use of OECs, it is important to emphasize the need for more experimental studies to clarify the exact nature of the repair capacity of these grafts in the treatment of SCI.
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Affiliation(s)
- Lígia Aline Centenaro
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS 90050-170, Brazil.
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Ossewaarde L, van Wingen GA, Rijpkema M, Bäckström T, Hermans EJ, Fernández G. Menstrual cycle-related changes in amygdala morphology are associated with changes in stress sensitivity. Hum Brain Mapp 2011; 34:1187-93. [PMID: 22162177 DOI: 10.1002/hbm.21502] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 09/18/2011] [Accepted: 10/05/2011] [Indexed: 11/10/2022] Open
Abstract
Premenstrual increases in negative mood are thought to arise from changes in gonadal hormone levels, presumably by influencing mood regulation and stress sensitivity. The amygdala plays a major role in this context, and animal studies suggest that gonadal hormones influence its morphology. Here, we investigated whether amygdala morphology changes over the menstrual cycle and whether this change explains differences in stress sensitivity. Twenty-eight young healthy women were investigated once during the premenstrual phase and once during the late follicular phase. T1-weighted anatomical images of the brain were acquired using magnetic resonance imaging and analyzed with optimized voxel-based morphometry. To measure mood regulation and stress sensitivity, negative affect was assessed after viewing strongly aversive as well as neutral movie clips. Our results show increased gray matter volume in the dorsal part of the left amygdala during the premenstrual phase when compared with the late follicular phase. This volume increase was positively correlated with the premenstrual increase in stress-induced negative affect. This is the first study showing structural plasticity of the amygdala in humans at the macroscopic level that is associated with both endogenous gonadal hormone fluctuations and stress sensitivity. These results correspond with animal findings of gonadal hormone-mediated neural plasticity in the amygdala and have implications for understanding the pathogenesis of specific mood disorders associated with hormonal fluctuations.
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Affiliation(s)
- Lindsey Ossewaarde
- Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, The Netherlands.
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Stigger F, do Nascimento PS, Dutra MF, Couto GK, Ilha J, Achaval M, Marcuzzo S. Treadmill training induces plasticity in spinal motoneurons and sciatic nerve after sensorimotor restriction during early postnatal period: new insights into the clinical approach for children with cerebral palsy. Int J Dev Neurosci 2011; 29:833-8. [PMID: 21925584 DOI: 10.1016/j.ijdevneu.2011.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 08/19/2011] [Accepted: 09/03/2011] [Indexed: 01/23/2023] Open
Abstract
The aim of the present study was to investigate whether locomotor stimulation training could have beneficial effects on the morphometric alterations of spinal cord and sciatic nerve consequent to sensorimotor restriction (SR). Male Wistar rats were exposed to SR from postnatal day 2 (P2) to P28. Control and experimental rats underwent locomotor stimulation training in a treadmill for three weeks (from P31 to P52). The cross-sectional area (CSA) of spinal motoneurons innervating hind limb muscles was determined. Both fiber and axonal CSA of myelinated fibers were also assessed. The growth-related increase in CSA of motoneurons in the SR group was less than controls. After SR, the mean motoneuron soma size was reduced with an increase in the proportion of motoneurons with a soma size of between 0 and 800 μm(2). The changes in soma size of motoneurons were accompanied by a reduction in the mean fiber and axon CSA of sciatic nerve. The soma size of motoneurons was reestablished at the end of the training period reaching controls level. Our results suggest that SR during early postnatal life retards the growth-related increase in the cell body size of motoneurons in spinal cord and the development of sciatic nerve. Additionally, three weeks of locomotor stimulation using a treadmill seems to have a beneficial effect on motoneurons' soma size.
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Affiliation(s)
- Felipe Stigger
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Brazil.
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Ilha J, Centenaro LA, Broetto Cunha N, de Souza DF, Jaeger M, do Nascimento PS, Kolling J, Ben J, Marcuzzo S, Wyse ATS, Gottfried C, Achaval M. The Beneficial Effects of Treadmill Step Training on Activity-Dependent Synaptic and Cellular Plasticity Markers After Complete Spinal Cord Injury. Neurochem Res 2011; 36:1046-55. [DOI: 10.1007/s11064-011-0446-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2011] [Indexed: 01/15/2023]
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Sex difference in cell proliferation in developing rat amygdala mediated by endocannabinoids has implications for social behavior. Proc Natl Acad Sci U S A 2010; 107:20535-40. [PMID: 21059913 DOI: 10.1073/pnas.1005003107] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The amygdala is a sexually dimorphic brain region critical for the regulation of social, cognitive, and emotional behaviors, but both the nature and the source of sex differences in the amygdala are largely unknown. We have identified a unique sex difference in the developing rat medial amygdala (MeA) that is regulated by cannabinoids. Newborn females had higher rates of cell proliferation than males. Treatment of neonates with the cannabinoid receptor agonist, WIN 55,212-2 (WIN), reduced cell proliferation in females to that of males and a wide range of WIN doses had no effect on cell proliferation in males. The effect of WIN on cell proliferation in the MeA was prevented by coinfusions of a CB2 but not CB1 receptor antagonist. Females had higher amygdala content of the endocannabinoid degradation enzymes, fatty acid amid hydrolase, and monoacylglycerol lipase than males, and lower amounts of the endocannabinoids 2-arachidonoylglycerol and N-arachidonylethanolamide (anandamide). Inhibition of the degradation of 2-arachidonoylglycerol in females occluded the sex difference in cell proliferation. Analyses of cell fate revealed that females had significantly more newly generated glial cells but not more newly generated neurons than males, and treatment with WIN significantly decreased glial cell genesis in females but not males. Finally, early exposure to cannabinoids masculinized juvenile play behavior in females but did not alter this behavior in males. Collectively, our findings suggest that sex differences in endocannabinoids mediate a sex difference in glial cell genesis in the developing MeA that impacts sex-specific behaviors in adolescence.
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Descriptive findings on the morphology of dendritic spines in the rat medial amygdala. Neurosci Lett 2010; 483:152-6. [DOI: 10.1016/j.neulet.2010.07.083] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 07/23/2010] [Accepted: 07/28/2010] [Indexed: 12/16/2022]
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Dall’Oglio A, Ferme D, Brusco J, Moreira JE, Rasia-Filho AA. The “single-section” Golgi method adapted for formalin-fixed human brain and light microscopy. J Neurosci Methods 2010; 189:51-5. [DOI: 10.1016/j.jneumeth.2010.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 01/05/2023]
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Arpini M, Menezes IC, Dall’Oglio A, Rasia-Filho AA. The density of Golgi-impregnated dendritic spines from adult rat posterodorsal medial amygdala neurons displays no evidence of hemispheric or dorsal/ventral differences. Neurosci Lett 2010; 469:209-13. [DOI: 10.1016/j.neulet.2009.11.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 11/24/2009] [Accepted: 11/25/2009] [Indexed: 12/27/2022]
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Sex differences in NADPH-diaphorase activity in the rat posterodorsal medial amygdala. Brain Res 2009; 1305:31-9. [DOI: 10.1016/j.brainres.2009.09.110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 09/28/2009] [Accepted: 09/28/2009] [Indexed: 02/06/2023]
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25
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de Castilhos J, Hermel EES, Rasia-Filho AA, Achaval M. Influence of substitutive ovarian steroids in the nuclear and cell body volumes of neurons in the posterodorsal medial amygdala of adult ovariectomized female rats. Neurosci Lett 2009; 469:19-23. [PMID: 19925848 DOI: 10.1016/j.neulet.2009.11.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 01/06/2023]
Abstract
The volumes of the neuronal nucleus and the cell body in the left posterodorsal medial amygdala (MePD) of adult ovariectomized (OVX) female rats submitted to different hormonal therapies were studied here, aiming to reveal possible influence of substitutive sex steroids in these morphological parameters. One week following ovariectomy and at the end of treatments, brains were cut to semi-thin sections (1 microm) and stained with 1% toluidine blue for stereological estimations, carried out using the Cavalieri method and the technique of point counting. Both the volume of the neuronal nucleus and the soma showed a statistically significant difference when comparing the data among OVX females treated with vehicle (V), estradiol (EB) alone, EB plus progesterone (EB+P) or P alone [n=5 rats in each group; one-way ANOVA test, P<0.01 in both cases]. The Tukey test showed that OVX and EB+P treated females had higher mean neuronal nucleus and somatic volumes when compared to V (P<0.01) or EB alone (P<0.01). Also, OVX females treated with P alone showed larger mean neuronal nucleus and somatic volumes when compared to V (P<0.05). These results suggest that the neuronal nucleus and the somatic volumes can be modulated by substitutive ovarian hormones administered to OVX females, for which P can lead to higher results. These findings reveal additional epigenetic actions of the sex steroids in the MePD and new neuronal morphological features in adult female rats.
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Affiliation(s)
- Juliana de Castilhos
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul/ICBS, Porto Alegre, RS, Brazil
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Iacono D, Markesbery WR, Gross M, Pletnikova O, Rudow G, Zandi P, Troncoso JC. The Nun study: clinically silent AD, neuronal hypertrophy, and linguistic skills in early life. Neurology 2009; 73:665-73. [PMID: 19587326 DOI: 10.1212/wnl.0b013e3181b01077] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND It is common to find substantial Alzheimer disease (AD) lesions, i.e., neuritic beta-amyloid plaques and neurofibrillary tangles, in the autopsied brains of elderly subjects with normal cognition assessed shortly before death. We have termed this status asymptomatic AD (ASYMAD). We assessed the morphologic substrate of ASYMAD compared to mild cognitive impairment (MCI) in subjects from the Nun Study. In addition, possible correlations between linguistic abilities in early life and the presence of AD pathology with and without clinical manifestations in late life were considered. METHODS Design-based stereology was used to measure the volumes of neuronal cell bodies, nuclei, and nucleoli in the CA1 region of hippocampus (CA1). Four groups of subjects were compared: ASYMAD (n = 10), MCI (n = 5), AD (n = 10), and age-matched controls (n = 13). Linguistic ability assessed in early life was compared among all groups. RESULTS A significant hypertrophy of the cell bodies (+44.9%), nuclei (+59.7%), and nucleoli (+80.2%) in the CA1 neurons was found in ASYMAD compared with MCI. Similar differences were observed with controls. Furthermore, significant higher idea density scores in early life were observed in controls and ASYMAD group compared to MCI and AD groups. CONCLUSIONS 1) Neuronal hypertrophy may constitute an early cellular response to Alzheimer disease (AD) pathology or reflect compensatory mechanisms that prevent cognitive impairment despite substantial AD lesions; 2) higher idea density scores in early life are associated with intact cognition in late life despite the presence of AD lesions.
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Affiliation(s)
- D Iacono
- Division of Neuropathology, Department of Pathology, Johns Hopkins University, School of Medicine, Ross Building 558, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Further considerations on cortical haemodynamic changes and visual tasks. Clin Neurophysiol 2009; 120:1415-7. [DOI: 10.1016/j.clinph.2009.04.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/04/2009] [Accepted: 04/21/2009] [Indexed: 11/21/2022]
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de Castilhos J, Forti CD, Achaval M, Rasia-Filho AA. Dendritic spine density of posterodorsal medial amygdala neurons can be affected by gonadectomy and sex steroid manipulations in adult rats: A Golgi study. Brain Res 2008; 1240:73-81. [DOI: 10.1016/j.brainres.2008.09.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/21/2008] [Accepted: 09/01/2008] [Indexed: 10/21/2022]
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Quagliotto E, Neckel H, Riveiro DF, Casali KR, Mostarda C, Irigoyen MC, Dall'ago P, Rasia-Filho AA. Histamine in the posterodorsal medial amygdala modulates cardiovascular reflex responses in awake rats. Neuroscience 2008; 157:709-19. [PMID: 18955117 DOI: 10.1016/j.neuroscience.2008.09.053] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 09/03/2008] [Accepted: 09/29/2008] [Indexed: 11/18/2022]
Abstract
Centrally injected histamine (HA) affects heart rate (HR), arterial blood pressure (BP), and sympathetic activity in rats. The posterodorsal medial amygdala (MePD) has high levels of histidine decarboxylase, connections with brain areas involved with the modulation of cardiovascular responses, and is relevant for the pathogenesis of hypertension. However, there is no report demonstrating the role of the MePD histaminergic activity on the cardiovascular function in awake rats. The aims of the present work were: 1) to study the effects of two doses (10-100 nM) of HA microinjected in the MePD on basal cardiovascular recordings and on baroreflex- and chemoreflex-mediated responses; 2) to reveal whether cardiovascular reflex responses could be affected by MePD microinjections of (R)-alpha-methylhistamine (AH3), an agonist of the inhibitory autoreceptor H3; and, 3) to carry out a power spectral analysis to evaluate the contribution of the sympathetic and parasympathetic components in the variability of the HR and BP recordings. When compared with the control group (microinjected with saline, 0.3 microl), HA (10 nM) promoted an increase in the MAP50, i.e. the mean value of BP at half of the HR range evoked by the baroreflex response. Histamine (100 nM) did not affect the baroreflex activity, but significantly decreased the parasympathetic component of the HR variability, increased the sympathetic/parasympathetic balance at basal conditions (these two latter evaluated by the power spectral analysis), and promoted an impairment in the chemoreflex bradycardic response. Microinjection of AH3 (10 microM) led to mixed results, which resembled the effects of both doses of HA employed here. Present data suggest that cardiovascular changes induced by baroreceptors and chemoreceptors involve the histaminergic activity in the MePD. This neural regulation of reflex cardiovascular responses can have important implications for homeostatic and allostatic conditions and possibly for the behavioral displays modulated by the rat MePD.
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Affiliation(s)
- E Quagliotto
- Department of Physiological Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, R. Sarmento Leite 245, Porto Alegre 90170-050 RS, Brazil
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Abstract
The pathologic changes of Alzheimer disease (AD) evolve very gradually over decades before the disease becomes clinically manifest. Thus, it is not uncommon to find substantial numbers of Abeta plaques and neurofibrillary tangles in autopsy brains of older subjects with documented normal cognition, a state that we define as asymptomatic AD (ASYMAD). The goal of this study is to understand the morphometric substrate of ASYMAD subjects compared with mild cognitive impairment and definite AD cases. We used designed-based stereology to measure the volumes of neuronal cell bodies, nuclei, and nucleoli in 4 cerebral regions: anterior cingulate gyrus, posterior cingulate gyrus, primary visual cortex, and CA1 of hippocampus. We examined and compared autopsy brains from 4 groups (n = 15 each) of participants in the Baltimore Longitudinal Study of Aging: ASYMAD, mild cognitive impairment, AD, and age-matched controls. We found significant hypertrophy of the neuronal cell bodies, nuclei, and nucleoli of CA1 of hippocampus and anterior cingulate gyrus neurons in ASYMAD subjects compared with control and mild cognitive impairment cases. In the posterior cingulate gyrus and primary visual cortex, the hypertrophy was limited to the nuclei and nucleoli. The hypertrophy of cortical neurons and their nuclei and nucleoli in ASYMAD may represent an early reaction to the presence of neurotoxic Abeta or tau, or a compensatory mechanism that prevents the progression of the disease into dementia.
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Marcuzzo S, Ferreira Dutra M, Stigger F, Severo do Nascimento P, Ilha J, Kalil-Gaspar PI, Achaval M. Beneficial effects of treadmill training in a cerebral palsy-like rodent model: Walking pattern and soleus quantitative histology. Brain Res 2008; 1222:129-40. [DOI: 10.1016/j.brainres.2008.05.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 05/16/2008] [Accepted: 05/16/2008] [Indexed: 10/22/2022]
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Ilha J, Araujo RT, Malysz T, Hermel EES, Rigon P, Xavier LL, Achaval M. Endurance and resistance exercise training programs elicit specific effects on sciatic nerve regeneration after experimental traumatic lesion in rats. Neurorehabil Neural Repair 2008; 22:355-66. [PMID: 18326889 DOI: 10.1177/1545968307313502] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To evaluate the effects of endurance, resistance, and a combination of both types of exercise training on hindlimb motor function recovery and nerve regeneration after experimental sciatic nerve lesion in rats. METHODS Sciatic nerve crush was performed on adult male rats, and after 2 weeks of the nerve lesion, the animals were submitted to endurance, resistance, and a combination of endurance-resistance training programs for 5 weeks. Over the training period, functional recovery was monitored weekly using the Sciatic Functional Index (SFI) and histological and morphometric nerve analyses were used to assess the nerve regeneration at the end of the trainings. RESULTS The SFI values of the endurance-trained group reached the control values from the first posttraining week and were significantly better than both the resistance-trained group at the first, second, and third posttraining weeks and the concurrent training group at the first posttraining week. At the distal portion of the regenerating sciatic nerve, the endurance-trained group showed a greater degree of the myelinated fiber maturation than the sedentary, resistance-trained, and concurrent training groups. Furthermore, the endurance-trained group showed a smaller percentage area of endoneurial connective tissue and a greater percentage area of myelinated fibers than the sedentary group. CONCLUSION These data provide evidence that endurance training improves sciatic nerve regeneration after an experimental traumatic injury and that resistance training or the combination of 2 strategies may delay functional recovery and do not alter sciatic nerve fiber regeneration.
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Affiliation(s)
- Jocemar Ilha
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Brazil
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Morris JA, Jordan CL, Breedlove SM. Sexual dimorphism in neuronal number of the posterodorsal medial amygdala is independent of circulating androgens and regional volume in adult rats. J Comp Neurol 2008; 506:851-9. [PMID: 18076082 DOI: 10.1002/cne.21536] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The posterodorsal medial amygdala (MePD) in rodents integrates olfactory and pheromonal information, which, coupled with the appropriate hormonal signals, may facilitate or repress reproductive behavior in adulthood. MePD volume and neuronal soma size are greater in male rats than in females, and these sexual dimorphisms are maintained by adult circulating hormone levels. Castration of adult males causes these measures to shrink to the size seen in females 4 weeks later, whereas testosterone treatment of adult females for 4 weeks enlarges these measures to the size of males. We used stereological methods to count the number of cells in the MePD and found that, in addition to the sex difference in regional volume and soma size, males also have more MePD neurons than do females, yet these numbers are unaffected by the presence or absence of androgen in adults of either sex. Males also have more glial cells than do females, but, in contrast to the effects on neuronal number, the number of glial cells is affected by androgen in the right MePD of both sexes and, therefore, may contribute to regional volume changes in adulthood in that hemisphere. Thus, regional volume, neuronal size, and glial numbers vary in the MePD of adult rats in response to circulating androgens, but neuronal number does not. These results suggest that the sex difference in neuronal number in the rat MePD may be "organized" by androgens prior to adulthood, whereas regional volume, neuronal size, and glial numbers can be altered by androgens in adulthood.
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Affiliation(s)
- John A Morris
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824-1101, USA
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Rocha MIM, Mestriner RG, Hermel EES, Xavier LL, Rasia-Filho AA, Achaval M. Neuronal somatic volume of posteroventral medial amygdala cells from males and across the estrous cycle of female rats. Neurosci Lett 2007; 420:110-5. [PMID: 17517473 DOI: 10.1016/j.neulet.2007.04.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 04/17/2007] [Accepted: 04/20/2007] [Indexed: 01/22/2023]
Abstract
The posteroventral medial amygdala (MePV) is a brain area where gonadal hormones have neurotrophic effects in rats. The aim of the present study was to estimate the MePV neuronal somatic volume from males and diestrus, proestrus and estrus female Wistar rats (n=5 in each group) in an attempt to identify a possible sexual dimorphism in this parameter. The effect of laterality was also evaluated. The brains of adult animals were sectioned (1 microm), stained with 1% toluidine blue and serial-section reconstructions of each neuronal cell body were obtained. Images from both left and right MePV were studied and the somatic volume was estimated using the Cavalieri method in combination with the point counting technique. Results were compared according to sex and phase of the estrous cycle using a two-way ANOVA for repeated measures followed by the least significance difference test. Mean neuronal somatic volume showed a statistical difference among groups and the post hoc comparisons revealed that males present higher values than females in proestrus and estrus (p<0.05). On the other hand, neither a laterality effect (p=0.6) nor an interaction between groups and laterality (p=0.4) were found. Our results indicate that cell body volume in the MePV is distinct when comparing males to females in the different phases of the estrous cycle. Through dynamic changes modulated by sex steroids, it is likely that this morphological plasticity within the MePV may be affecting the functioning of local neurons and their integrated roles in neural circuits relevant for neuroendocrine control and reproductive behaviors.
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Affiliation(s)
- M Izabel M Rocha
- Programa de Pós-graduação em Ciências Biológicas - Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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