Effects of desipramine on neuronal responses to dopamine, noradrenaline, 5-hydroxytryptamine and acetylcholine in the caudate nucleus of the rat.
1 The sensitivity of single neurones to microelectrophoretically applied dopamine, noradrenaline (NA), 5-hydroxytryptamine (5-HT) and acetylcholing (ACh) was investigated in the caudate nucleus of the rat, anaesthetized with halothane. Both excitatory and depressant responses could be observed to each of the agonists. There was a high correlation between the direction of responses to dopamine and noradrenaline, whereas there was no significant correlation between the direction of responses to dopamine and ACh. 2 The effect of desipramine was studied on both excitatory and depressant responses to dopamine, NA and 5-HT, and on excitatory responses to ACh. Both potentiation and antagonism of neuronal responses to monoamines and ACh could be observed after a brief application of desipramine. 3 Excitatory responses to glutamate were not affected by desipramine. 4 The observation that responses to dopamine and NA can be potentiated by desipramine in the caudate nucleus suggests that uptake blockade is not a prerequisite for potentiation. 5 It is suggested that the potentiation of neuronal responses to dopamine by desipramine may be responsible for the therapeutic efficacy of desipramine in Parkinson's disease.
D000109:Acetylcholine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects*; D003891:Desipramine / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology*; D004357:Drug Synergism; D005971:Glutamates / Q000494:pharmacology; D007478:Iontophoresis; D008297:Male; D009474:Neurons / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*; D013997:Time Factors
D005971:Glutamates; D012701:Serotonin; D000109:Acetylcholine; D003891:Desipramine; D004298:Dopamine; D009638:Norepinephrine