Navegando por Palavras-chave "inhibitory avoidance"
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- ItemAcesso aberto (Open Access)Anterograde effects of a single electroconvulsive shock on inhibitory avoidance and on cued fear conditioning(Associação Brasileira de Divulgação Científica, 1998-08-01) Oliveira, Maria Gabriela Menezes de [UNIFESP]; Bueno, Orlando Francisco Amodeo [UNIFESP]; Gugliano, Eric Boragan [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)A single electroconvulsive shock (ECS) or a sham ECS was administered to male 3-4-month-old Wistar rats 1, 2, and 4 h before training in an inhibitory avoidance test and in cued classical fear conditioning (measured by means of freezing time in a new environment). ECS impaired inhibitory avoidance at all times and, at 1 or 2 h before training, reduced freezing time before and after re-presentation of the ECS. These results are interpreted as a transient conditioned stimulus (CS)-induced anxiolytic or analgesic effect lasting about 2 h after a single treatment, in addition to the known amnesic effect of the stimulus. This suggests that the effect of anterograde learning impairment is demonstrated unequivocally only when the analgesic/anxiolytic effect is over (about 4 h after ECS administration) and that this impairment of learning is selective, affecting inhibitory avoidance but not classical fear conditioning to a discrete stimulus.
- ItemSomente MetadadadosEffects of the M1 Muscarinic Antagonist Dicyclomine on Emotional Memory Retrieval(Amer Psychological Assoc, 2016) Soares, Juliana Carlota Kramer [UNIFESP]; Perfetto, Juliano Genaro [UNIFESP]; Antonio, Bruno Brito [UNIFESP]; Oliveira, Maria Gabriela Menezes [UNIFESP]Extensive research has shown the involvement of the central cholinergic system in the acquisition and consolidation of tasks involving conditioned fear responses, such as those observed in contextual fear conditioning (CFC), tone fear conditioning (TFC) and inhibitory avoidance (IA). However, there are few data concerning the role of this system in the memory retrieval process. Therefore, the present study aimed to compare the effects of the administration of an M1 antagonist on retrieval during these tasks. For each behavioral procedure, groups of male Wistar rats were trained. Twenty-four hr later, they were treated with different doses of dicyclomine (16, 32, or 64 mg/kg, i.p.) or with saline 30 min before the test session. The results showed that dicyclomine at doses of 16 and 32 mg/kg impaired CFC without interfering with IA performance. Moreover, only 64 mg/kg impaired TFC. These data suggest that M1 muscarinic receptors contribute to memory retrieval in CFC and TFC but are not essential for retrieval in IA.
- ItemSomente MetadadadosEffects of the M1 Muscarinic Antagonist Dicyclomine on Emotional Memory Retrieval(Amer Psychological Assoc, 2016) Soares, Juliana Carlota Kramer [UNIFESP]; Perfetto, Juliano Genaro [UNIFESP]; Antonio, Bruno Brito [UNIFESP]; Oliveira, Maria Gabriela Menezes [UNIFESP]Extensive research has shown the involvement of the central cholinergic system in the acquisition and consolidation of tasks involving conditioned fear responses, such as those observed in contextual fear conditioning (CFC), tone fear conditioning (TFC) and inhibitory avoidance (IA). However, there are few data concerning the role of this system in the memory retrieval process. Therefore, the present study aimed to compare the effects of the administration of an M1 antagonist on retrieval during these tasks. For each behavioral procedure, groups of male Wistar rats were trained. Twenty-four hr later, they were treated with different doses of dicyclomine (16, 32, or 64 mg/kg, i.p.) or with saline 30 min before the test session. The results showed that dicyclomine at doses of 16 and 32 mg/kg impaired CFC without interfering with IA performance. Moreover, only 64 mg/kg impaired TFC. These data suggest that M1 muscarinic receptors contribute to memory retrieval in CFC and TFC but are not essential for retrieval in IA.
- ItemSomente MetadadadosRole of muscarinic M1 receptors in inhibitory avoidance and contextual fear conditioning(Elsevier B.V., 2006-09-01) Kramer Soares, Juliana Carlota; Fornari, Raquel Vecchio; Menezes Oliveira, Maria Gabriela; Universidade Federal de São Paulo (UNIFESP)The objective of the present study was to observe the effects of pre-training or post-training administration of dicyclomine, a M1 muscarinic antagonist, on inhibitory avoidance (IA) and contextual fear conditioning (CFC) and to investigate if the effects observed with the pre-training administration of dicyclomine are state-dependent. for each behavioral procedure (IA and CFC) groups of Wistar male rats were treated with saline or dicyclomine either 30 min before training (pre-training), immediately after training or 30 min before training/30 min before test (pre-training/pre-test). the animals were tested 24 h after training. the acquisition of IA and CFC was impaired by pre-training administration of dicyclomine. the consolidation of both tasks was not affected by dicyclomine given immediately after training. Pre-training/pre-test administration of dicyclomine impaired both tasks, an effect similar to that observed in the group which only received pre-training administration. Pre-test treatment induced dissociation between both tasks, impairing CFC retrieval, without interfering with the animals avoidance response. These results show that the dicyclomine did not affect IA and CFC consolidation, suggesting specific involvement of M1 muscarinic receptor only in acquisition these tasks, and these effects was not state-dependent. However, it is possible that the retrieval of these tasks may be mediated, at least in part, by different neurochemical mechanisms and may be dissociated by dicyclomine. (c) 2006 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosSocial stress does not interact with paradoxical sleep deprivation-induced memory impairment(Elsevier B.V., 2002-02-01) Dametto, M.; Suchecki, D.; Bueno, OFA; Moreira, K. M.; Tufik, S.; Oliveira, MGM; Universidade Federal de São Paulo (UNIFESP)Extensive evidence has linked both paradoxical sleep (PS) and stress to memory processing. the purpose of the present study was to examine the effect of social instability stress on memory and to verify whether this stress interferes with the amnesic effect of PS deprivation using the modified multiple platform method. in addition to the PS-deprived group (put onto narrow platforms inside the deprivation tanks) two control groups were used: one of them remained in its home-cages and the other was placed inside the deprivation tanks, onto a grid that contained large platforms on it. All groups were subdivided in socially stable and unstable conditions. Immediately after 96 h of sleep deprivation, the animals were trained in three different memory tasks: inhibitory avoidance, classical fear conditioning to a discrete stimulus and contextual fear conditioning. Twenty-four hours after training, the animals were tested in order to assess task acquisition. the results showed that social instability did not impair the performance of animals nor interacted with PS deprivation in any of the tasks. Grid control animals presented a selective impairment in the inhibitory avoidance task and contextual, but not in the classical, fear conditioning task, compared to cage control rats. This finding could be due to the stress to which grid control animals were exposed (humidity and luminosity) during the manipulation period. PS-deprived animals exhibited poorer performance than the other groups in all tasks. As they also showed an increased threshold to shock-induced vocalisation, but not to flinch response, it is not possible to completely rule out a decreased response to noxious stimulation as a contributing factor for the present results with PS deprivation. (C) 2002 Elsevier Science B.V. All rights reserved.