Dopaminergic neurons: An in vivo system for measuring drug interactions with presynaptic receptors

摘要: An in vivo system has been used to investigate the ability of dopamine agonists and antagonists alter synthesis by acting at what appear be presynaptic receptors. In order eliminate postsynaptically induced changes caused effects these drugs on firing rate neurons, gammabutyrolactone was administered block impulse flow nigro-neostriatal pathway. The accumulation Dopa rat striatum after administration decarboxylase inhibitor as an index striatal tyrosine hydroxylase activity. It found that agonists, apomorphine or ET-495 [1-(2′-pyrimidyl)-piperonyl-piperazine], modified apparent activity when blocked neurons. This effect could prevented low doses loxapine haloperidol spiroperidol. Chlorpromazine, fluphenazine, thioridizine were much less effective than butyrophenones blocking apomorphine. Molindone (+) butaclamol, but not (-) reversed agonist effects, pimozide a weak blocker clozapine had no all. All neuroleptics except butaclamol significant increase intact. Compared with phenothiazines appeared potent reversing behavioral this agonist. Possible functional significance receptors are considered.