Navegando por Palavras-chave "Hippocampal neurogenesis"
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- ItemAcesso aberto (Open Access)Efeitos do estresse crônico brando e imprevisível sobre aspectos comportamentais e neurobiológicos relacionados à ansiedade e ao pânico(Universidade Federal de São Paulo (UNIFESP), 2016-07-11) Andrade, José Simões de [UNIFESP]; Viana, Milena de Barros [UNIFESP]; http://lattes.cnpq.br/3053794724319601; http://lattes.cnpq.br/3684532754100660; Universidade Federal de São Paulo (UNIFESP)Previous results show that elevated T-maze (ETM) avoidance responses are facilitated by acute restraint. Escape, on the other hand, was unaltered. To examine if the magnitude of the stressor is an important factor influencing these results, we investigated the effects of unpredictable chronic mild stress (UCMS) on ETM avoidance and escape measurements. Analysis of Fos protein immunoreactivity (Fos-ir) was used to map areas activated by stress exposure in response to ETM avoidance and escape performance. Additionally, the effects of the UCMS protocol on the number of cells expressing the marker of migrating neuroblasts doublecortin (DCX) in the hippocampus were investigated. Corticosterone serum levels were also measured. Results showed that UCMS facilitates ETM avoidance, not altering escape. In unstressed animals, avoidance performance increases Fos-ir in the cingulate cortex, hippocampus (dentate gyrus) and basomedial amygdala, and escape increases Fos-ir in the dorsolateral periaqueductal gray and locus ceruleus. In stressed animals submitted to ETM avoidance, increases in Fos-ir were observed in the cingulate cortex, ventrolateral septum, hippocampus, hypothalamus, amygdala, dorsal and median raphe nuclei. In stressed animals submitted to ETM escape, increases in Fos-ir were observed in the cingulate cortex, periaqueductal gray and locus ceruleus. Also, UCMS exposure decreased the number of DCX-positive cells in the dorsal and ventral hippocampus and increased corticosterone serum levels. It is interesting to mention that exposure on ETM avoidance increases the expression of CRF mRNA in the PVN, medial amygdala, central amygdala, hippocampus (cornus Ammon), hippocampus (dentante gyrus) and dorsomedial hypothamalus. Escape measurement, increases the expression of CRF mRNA in the PVN, central amygdala, hippocampus (cornus Ammon) and VlPAG. In stressed animals submitted to ETM avoidance, increases the expression of CRF mRNA in the cingulated cortex, BNST, dorsomedial hypothamalus, hippocampus (cornus Ammon), hippocampus (dentante gyrus) and VlPAG. Escape measurement, increases the expression of CRF mRNA in the medial amygdale and VlPAG. These data suggest that the anxiogenic effects of UCMS are related to the activation of specific neurobiological circuits that modulate anxiety and confirm that this stress protocol activates the hypothalamus?pituitary?adrenal axis and decreases hippocampal adult neurogenesis.
- ItemSomente MetadadadosEffects of chronic treatment with corticosterone and imipramine on fos immunoreactivity and adult hippocampal neurogenesis(Elsevier B.V., 2013-02-01) Diniz, Leila [UNIFESP]; Santos, Thays Brenner dos [UNIFESP]; Britto, Luiz Roberto Giorgetti de; Céspedes, Isabel Cristina [UNIFESP]; Garcia, Marcia Carvalho [UNIFESP]; Spadari-Bratfisch, Regina Celia [UNIFESP]; Medalha, Carla Christina [UNIFESP]; Castro, Glaucia Monteiro de [UNIFESP]; Montesano, Fábio Tadeu [UNIFESP]; Viana, Milena de Barros [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)In a previous study we showed that rats chronically treated with corticosterone (CORT) display anxiogenic behavior, evidenced by facilitation of avoidance responses in the elevated T-maze (ETM) model of anxiety. Treatment with the tricyclic antidepressant imipramine significantly reversed the anxiogenic effects of CURT, while inhibiting ETM escape, a response related to panic disorder. To better understand the neurobiological mechanisms underlying these behavioral effects, analysis of c-fos protein immunoreactivity (fos-ir) was used here to map areas activated by chronic CORT (200 mg pellets, 21-day release) and imipramine (15 mg/kg, IP) administration. We also evaluated the number of cells expressing the neurogenesis marker doublecortin (DCX) in the hippocampus and measured plasma CURT levels on the 21st day of treatment. Results showed that CURT increased fos-ir in the ventrolateral septum, medial amygdala and paraventricular hypothalamic nucleus and decreased fos-ir in the lateral periaqueductal gray. Imipramine, on the other hand, increased fos-ir in the medial amygdala and decreased fos-ir in the anterior hypothalamus. CURT also decreased the number of DCX-positive cells in the ventral and dorsal hippocampus, an effect antagonized by imipramine. CURT levels were significantly higher after treatment. These data suggest that the behavioral effects of CURT and imipramine are mediated through specific, at times overlapping, neuronal circuits, which might be of relevance to a better understanding of the physiopathology of generalized anxiety and panic disorder. (c) 2012 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosImpact of neonatal anoxia on adult rat hippocampal volume, neurogenesis and behavior(Elsevier Science Bv, 2016) Takada, Silvia Honda; Motta-Teixeira, Livia Clemente; Machado-Nils, Aline Vilar; Lee, Vitor Yonamine; Sampaio, Carlos Alberto; Polli, Roberson Saraiva [UNIFESP]; Malheiros, Jackeline Moraes [UNIFESP]; Takase, Luiz Fernando; Kihara, Alexandre Hiroaki; Covolan, Luciene [UNIFESP]; Xavier, Gilberto Fernando; Nogueira, Maria InesNeonates that suffer oxygen deprivation during birth can have long lasting cognitive deficits, such as memory and learning impairments. Hippocampus, one of the main structures that participate in memory and learning processes, is a plastic and dynamic structure that conserves during life span the property of generating new cells which can become neurons, the so-called neurogenesis. The present study investigated whether a model of rat neonatal anoxia, that causes only respiratory distress, is able to alter the hippocampal volume, the neurogenesis rate and has functional implications in adult life. MRI analysis revealed significant hippocampal volume decrease in adult rats who had experienced neonatal anoxia compared to control animals for rostra!, caudal and total hippocampus. In addition, these animals also had 55.7% decrease of double-labelled cells to BrdU and NeuN, reflecting a decrease in neurogenesis rate. Finally, behavioral analysis indicated that neonatal anoxia resulted in disruption of spatial working memory, similar to human condition, accompanied by an anxiogenic effect. The observed behavioral alterations caused by oxygen deprivation at birth might represent an outcome of the decreased hippocampal neurogenesis and volume, evidenced by immunohistochemistry and MRI analysis. Therefore, based on current findings we propose this model as suitable to explore new therapeutic approaches. (C) 2015 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosImpact of neonatal anoxia on adult rat hippocampal volume, neurogenesis and behavior(Elsevier Science Bv, 2016) Takada, Silvia Honda; Motta-Teixeira, Livia Clemente; Machado-Nils, Aline Vilar; Lee, Vitor Yonamine; Sampaio, Carlos Alberto; Polli, Roberson Saraiva [UNIFESP]; Malheiros, Jackeline Moraes [UNIFESP]; Takase, Luiz Fernando; Kihara, Alexandre Hiroaki; Covolan, Luciene [UNIFESP]; Xavier, Gilberto Fernando; Nogueira, Maria InesNeonates that suffer oxygen deprivation during birth can have long lasting cognitive deficits, such as memory and learning impairments. Hippocampus, one of the main structures that participate in memory and learning processes, is a plastic and dynamic structure that conserves during life span the property of generating new cells which can become neurons, the so-called neurogenesis. The present study investigated whether a model of rat neonatal anoxia, that causes only respiratory distress, is able to alter the hippocampal volume, the neurogenesis rate and has functional implications in adult life. MRI analysis revealed significant hippocampal volume decrease in adult rats who had experienced neonatal anoxia compared to control animals for rostra!, caudal and total hippocampus. In addition, these animals also had 55.7% decrease of double-labelled cells to BrdU and NeuN, reflecting a decrease in neurogenesis rate. Finally, behavioral analysis indicated that neonatal anoxia resulted in disruption of spatial working memory, similar to human condition, accompanied by an anxiogenic effect. The observed behavioral alterations caused by oxygen deprivation at birth might represent an outcome of the decreased hippocampal neurogenesis and volume, evidenced by immunohistochemistry and MRI analysis. Therefore, based on current findings we propose this model as suitable to explore new therapeutic approaches. (C) 2015 Elsevier B.V. All rights reserved.