Navegando por Palavras-chave "Estereologia"
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- ItemAcesso aberto (Open Access)Avaliação comparativa da expressão de c-Fos no cortex cerebral de ratos e saguis após estimulação com pentilenotetrazol(Universidade Federal de São Paulo (UNIFESP), 2018-04-26) Magalhães, Stefani Alves [UNIFESP]; Mello, Luiz Eugenio Araujo de Moraes [UNIFESP]; http://lattes.cnpq.br/4462750801249231; http://lattes.cnpq.br/4494287187001621; Universidade Federal de São Paulo (UNIFESP)Introduction: Previous evidence from our laboratory indicate a potential mechanism that might support the fact that primates exhibit greater cogntive integration capacity as a result of the activation of different structures of the central nervous system, as compared to rodents. The current study might contribute to explain the different neural processing capacities presented by these animals as compared to other mammal orders. Aims: To search for stronger evidence that could confirm our previous findings here we analyzed the patterns of c-Fos expression in neocortical structures of rats and marmosets using a more robust quantitative technique and evaluating a larger number of brain areas. Twenty-seven rats (Wistar) and 21 marmosets (Callithrix jacchus) were euthanized at different times after seizures induced by the GABAergic antagonist pentylenetetrazol (PTZ), and then distributed among the control groups (animals without seizures); PTZ group 0.5h; 1, 2, 3, 6, 9 and 12h after PTZ induction. The biological material was processed for the immunohistochemical detection of c-Fos and the cell count was performed by means of the stereology technique with a StereoInvestigator® program. Results: Marmosets had a c-Fos expression that was notably stronger (5x) and longer (up to 3 hours) than rats. Yet, the expression in rats presented similar patterns of expression according to the function of the structures (associative, cortical and motor functions), which was not observed for marmosets. Conclusions: Our results provide evidence that the marmoset brain has a greater neuronal activation after intense stimulation by means of PTZ and a more complex pattern of brain activation, which are indicative of a brain structure with a higher degree of specialization than that seen for rats. Although expected, these functional differences had never been characterized before, and may contribute for the understanding of the different neuronal processing capacities of these mammals orders.
- ItemAcesso aberto (Open Access)Estudo morfológico do hipocampo de uma espécie de primata da Amazônia: Cebus apella, (Linnaeus, 1758)(Universidade Federal de São Paulo (UNIFESP), 2010-11-24) Torres, Laila Brito [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The nonhuman primates constitute irreplaceable animal models for research areas in which their close evolutionary relationship to humans ensures high fidelity models with predictive and discriminative abilities that may not be available in other species. The Cebus apella, a New World primate specie belonging to the Cebidae family, Cebinae suborder (Linnaeus, 1758) are commonly used in biomedical and behavior research being the specie of choice for many cognitive experimental tasks. The hippocampus, a highly plastic limbic structure situated in the temporal lobe is important for learning and memory consolidation. In this way, the aim of this study was to characterize quantitatively and qualitatively the Parvalbumin positive cells in the hippocampal formation of the Cebus monkey and also estimate the volume and neuronal number in their different subfields using an optical fractionator design method. The results obtained in our study will be useful for many experimental designs in translational medicine.
- ItemSomente MetadadadosIndução e expressão da sensibilização locomotora à cocaína e estruturas neuroanatômicas envolvidas nesse fenômeno: um estudo comportamental e estereológico(Universidade Federal de São Paulo (UNIFESP), 2017-05-31) Santos, Renan dos [UNIFESP]; Longo, Beatriz Monteiro [UNIFESP]; http://lattes.cnpq.br/0245964878412260; http://lattes.cnpq.br/5723339206716637; Universidade Federal de São Paulo (UNIFESP)Drug addiction has been one of the major concerns of modern society. Given this, it has been the focus of study in several segments of the human, medical and biological sciences. Epidemiological data, particularly in Brazil, show that the consumption of some drugs has been growing steadily over the years, a fact that serves as motivation for biological research that seeks to characterize this phenomenon. Studies have shown that drugs with abuse potential modulate the functioning of various brain structures in the limbic system, both in humans and rodents. Thus, the present study aimed to characterize the behavioral effects of locomotor sensitization to cocaine. In addition, we aimed to characterize neuroanatomical structures involved in this phenomenon, through the stereological quantification of Fos protein, a three-dimensional technique recognized for its excellence in unbiased quantification. For this, in the behavioral experiment 1, female Swiss mice were distributed in three groups: Sal-Sal, Coc-Sal, Sal-Coc. All animals were habituated for three consecutive days in the open field apparatus. The next day, the conditioning process began. Thus, animals from the Sal-Sal group received a first i.p. injection of saline solution and then were exposed to the open field for 10 minutes and returned to the housing box. Two hours later, these animals received a second saline injection and were immediately returned to the housing box. The animals of the Coc-Sal and Sal-Coc groups were handled in the same way except that the Coc-Sal group received the first injection of 10 mg / kg of cocaine and the second of saline, while the Sal-Coc group received the first injection of saline and the second dose of cocaine at a dose of 10 mg / kg. Thus, in the Coc-Sal group, cocaine was matched to the environmental context, not to the Sal-Coc group. Pharmacological treatment (cocaine or saline) occurred intermittently for 15 days. After the last day of conditioning, the animals were euthanized for a subsequent immunohistochemical procedure. In the behavioral experiment 2, the protocol followed in the same way, however, after the conditioning period, the animals remained without being manipulated experimentally for 10 days, after this interval, all the animals were challenged with cocaine and soon after, euthanized to later perform the immunohistochemical procedure. The behavioral results indicated that only the animals that were treated with cocaine in a similar way to the environmental context showed a marked locomotor response, both in behavioral experiment 1 (characterizing the development of locomotor sensitization) and behavioral experiment 2 (characterizing the expression of locomotor sensitization). Regarding Fos protein expression, there was a greater expression of this marker of neural activity in the medial dorsal prefrontal cortex, nucleus accumbens shell, basolateral amygdala and ventral integumentary area of cocaine-conditioned animals in the developmental phase of locomotive sensitization. While in the expression phase of locomotor sensitization, there was greater expression of Fos in the prefrontal cortex medial dorsum, nucleus accumbens core and shell, basolateral amygdala and central amygdala. In the orbitofrontal cortex, the animals that received cocaine in a context-matched form at the development stage of the sensitization had a lower Fos expression. Therefore, this data indicates that the environmental context plays a prominent role in the development and expression of locomotor sensitization, and that structures that make up the limbic system, but not all, contribute to this phenomenon.
- ItemAcesso aberto (Open Access)Influência do exercício físico na Bainha de Mielina hipocampal de ratos idosos: uma abordagem estereológica(Universidade Federal de São Paulo, 2023-07-27) Graciani, Alexandre Lebedev [UNIFESP]; Arida, Ricardo Mario [UNIFESP]; Gutierre, Robson Campos [UNIFESP]; http://lattes.cnpq.br/3048510516924444; http://lattes.cnpq.br/8352745170435172; http://lattes.cnpq.br/4114807793628325Objetivo: Investigar diferenças morfológicas e funcionais entre os hipocampos de animais idosos submetidos ou não a um programa de exercício aeróbico Métodos: dez ratos Wistar machos com 18 meses de idade foram divididos em grupo controle (n=5) e exercício (n=5). Animais do grupo exercício foram submetidos a um programa de treinamento aeróbico por 2 meses (5 dias por semana). Vinte e quatro horas após a última sessão de treinamento, os hipocampos dos dois grupos foram pesados, medidos pelo método de Scherle e processados para estudo histológico. Secções histológicas foram coradas com Hematoxilina e Eosina (HE) r Sudan Black B + Brasalumen de Mayer para estudo morfológico e submetidas ao método histoquímico de Klüver-Barrera para identificação da bainha de mielina. Foram identificados astrócitos, oligodendrócitos, neurônios piramidais e granulares pelo HE, micróglias fagocíticas e inativas foram identificadas pelo método do Sudan Black B + Brasalumen de Mayer. Foi aplicada estereologia para avaliar densidade numérica de células e densidade volumétrica de mielina. O Teste t de Student foi aplicado. Resultados: Avaliação da bainha de mielina mostrou aumento significativo de densidade no grupo exercício (p= 0,002), enquanto oligodendrócitos (p=0,084), micróglias fagocíticas (p=0,011) e micróglias totais (p=0,072) mostraram aumento significativo de densidade no grupo controle. Demais células analisadas não mostraram significância. Conclusão: Exercício físico é bastante efetivo na proteção da bainha de mielina contra a degeneração decorrente da idade. A redução da densidade total de micróglias, assim como de micróglias fagocíticas, são indícios do papel anti-inflamatório do exercício, assim como de sua capacidade de prevenir acúmulo de detritos no meio extracelular. Em contrapartida, o aumento da densidade de oligodendrócitos produzidos em resposta ao envelhecimento não é tão efetivo, o que dá destaque à efetividade do exercício como agente protetor contra o envelhecimento.