RESUMO
AIM To investigate the effects of several 5-hydroxytryptamine(5-HT) subtype receptor antagonists on late slow excitatory postsynaptic potential(LS-EPSP) of the neurons of guinea pig inferior mesenteric ganglion(IMG). METHODS Intracellular recordings were made from neurons of the isolated guinea pig IMG. RESULTS Cyproheptadine and BRL 24924 suppressed LS-EPSP of 5-HT sensitive neurons reversibly, while mianserin, MDL 72222 and spiperone showed no significant effect. Continuous superfusion of IMG with MCPP suppressed LS-EPSP of 5-HT sensitive neurons by 5-HT 1P receptor desensitizated. CONCLUSION LS-EPSP of 5-HT sensitive neuron is mediated by 5-HT 1P subtype receptor.
RESUMO
This work was carried out to investigate the effects of clonidine on some electrophysiological properties of the neurons of guinea-pig celiac ganglia in vitro, using the technique of intracellula.r recording. 54 neurons were examined, among which 18 neurons were found to be sensitive to clonidine. There were 3 reaction types in the sensitive cells, depolarization with decrease of membrane resistance, hyperpolarization with increase of membrane resistance and biphasic reaction ( depolarization followed by hyperpolarization ) . Clonidine depolarization was not blocked by low Ca