Navegando por Palavras-chave "cholinergic system"
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- ItemSomente MetadadadosCholinergic modulation of inhibitory avoidance impairment induced by paradoxical sleep deprivation(Elsevier B.V., 2000-05-01) Bueno, OFA; Oliveira, MGM; Lobo, L. L.; Morais, P. R.; Melo, FHM; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)1. Male Wister rats were submitted to paradoxical sleep deprivation for 96 hr by a modified multiple platform technique.2. Training of step-through inhibitory avoidance was performed immediately after the last day of paradoxical sleep deprivation. Twenty-four hr after training the animals were submitted to the retention test.3. in Experiment 1, pilocarpine (4 mg/kg, i.p.) or atropine (4 mg/kg, i.p.) were administered daily during. the paradoxical sleep deprivation period. Pilocarpine, but not atropine, reversed the impairment induced by PS deprivation.4. in Experiment 2, pilocarpine (4, 8 and 12 mg/kg, i.p.) was injected 1 hr before training in order to verify if the reversal of memory impairment was an effect secondary to residual enhanced blood levels of pilocarpine during training. Acute treatment with pilocarpine, in any dose, did not reverse the impairment produced by paradoxical sleep deprivation5. Activation of the cholinergic system during the period ol:deprivation is able to prevent memory deficits induced by paradoxical sleep deprivation.
- ItemSomente MetadadadosDifferences in central and peripheral responses to oxotremorine in young and aged rats(Elsevier B.V., 1999-03-01) Espinola, E. B.; Oliveira, MGM; Carlini, E. A.; Universidade Federal de São Paulo (UNIFESP)Few studies have investigated the pharmacological response of agents that act on the cholinergic system from the point of view of age. the present article investigated central responses (tremor) and peripheral responses (chromodacryorrhea) subsequent to the administration of oxotremorine to young (3-6 months of age) and aged rats (24-30 months of age). the aged rats presented greater duration and intensity of tremor in three doses utilized (0.25, 0.5, and 1.0 mg/kg) compared to young rats. These two groups of animals did differ in latency for the onset of the tremor. the aged rats presented more intense chromodacryorrhea than the young rats in all utilized doses. These data are indicative that both responses-central and peripheral-are affected by aging, possibly as a result of pharmacokinetic alterations and/or alterations in functionality of the cholinergic system in aged rats. (C) 1999 Elsevier Science Inc.
- ItemSomente MetadadadosTreatment with dexamethasone alters yawning behavior induced by cholinergic but not dopaminergic agonist(Elsevier B.V., 1999-01-15) Hipólide, Débora Cristina [UNIFESP]; Lobo, Leticia Leite [UNIFESP]; Medeiros, Roberta de; Neumann, Beatrice Rosaura Guaragna [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Because stressful manipulations have been reported to modify drug-induced yawning, the present study investigated the effects of single and repeated treatment with a synthetic glucocorticoid, dexamethasone (DEXA) on apomorphine- and pilocarpine-induced yawning in male rats. Neither single nor repeated treatment with DEXA altered apomorphine-induced yawning. Single administration of DEXA, however, resulted in an increased number of yawns induced by pilocarpine. Conversely, repeated administration of DEXA led to a decreased number of yawns induced by pilocarpine. In conclusion, the present findings show that dopaminergic and cholinergic are distinctly altered by DEXA, in terms of yawning behavior when animals received DEXA. (C) 1999 Elsevier Science, Inc.