PMID: 3320346Dec 1, 1987Paper

Comparative dopamine-cholinergic mechanisms in the olfactory tubercle and the striatum: effects of metoclopramide

The Journal of Pharmacology and Experimental Therapeutics
H Suarez-RocaL X Cubeddu

Abstract

The olfactory tubercle (OT) is a limbic structure containing high dopamine (DA) and acetylcholine (ACh) concentrations. We performed a comparative study of the DA-ACh interactions, the efficacy of autoreceptor control and the effects of metoclopramide in the OT and the nucleus caudate (striatum). Rabbit brain slices from both regions of the same animal were prelabeled with radioactive DA and/or choline and then superfused. Comparable magnitude of DA and ACh release was evoked by electrical stimulation from both regions. DA release was unaltered, whereas ACh release was inversely related to the stimulation frequency, both in OT and striatum. Apomorphine (APO), a D1-D2 agonist, an LY-171555 (LY), a D2 agonist, inhibited DA and ACh release from OT and striatum with similar EC50 and Emax (maximal percentage of inhibition). However, the maximal degree of inhibition of ACh release achieved with APO, LY or DA in the OT was only one-half that observed in the striatum. In both regions, the inhibitory effects of DA agonists on DA and ACh release were reduced markedly when the number of electrical pulses and/or the frequency of stimulation were increased. l-Sulpiride, a DA D2 antagonist, increased the evoked release of DA and ACh from OT ...Continue Reading

Related Concepts

Related Feeds

Basal Ganglia

Basal Ganglia are a group of subcortical nuclei in the brain associated with control of voluntary motor movements, procedural and habit learning, emotion, and cognition. Here is the latest research.