title: Cholinergic action in the nucleus accumbens: modulation of dopamine and acetylcholine release.
abstract: The action of oxotremorine and acetylcholine on the release of dopamine and acetylcholine from tissue slices of the rat nucleus accumbens was studied. Oxotremorine significantly enhanced the release of [14C]-dopamine evoked by 34 mMK+ and the EC50 for this action was 1.5 X 10(-7)M. A maximal enhancement (30%) for this effect was reached at 2 X 10(-7)M oxotremorine. A further enhancement of dopamine release occurred at concentrations of oxotremorine greater than 10(-4)M. The action of oxotremorine on [14C]-dopamine release was calcium-dependent and blocked by atropine (10(-4) M) but not mecamylamine (up to 10(-4) M). Oxotremorine affected [3H]-acetylcholine release differentially, inhibiting the K+-evoked release of [3H]-acetylcholine at concentrations greater than 10(-5) M. The IC50 for this process was 4.3 X 10(-5) M. Acetylcholine (8 X 10(-4) M) showed a similar pattern of action to oxotremorine: it enhanced the K+-evoked release of [14C]-dopamine (50%) and inhibited the K+-evoked release of [3H]-acetylcholine (30%). The mechanism of action of oxotremorine on dopamine release is discussed in terms of a presynaptic receptor-mediated process.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D010095:Oxotremorine / Q000494:pharmacology; D010277:Parasympathomimetics / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology; D011976:Receptors, Muscarinic / Q000502:physiology; D012686:Septal Nuclei / Q000187:drug effects*
chemical_list: D010277:Parasympathomimetics; D011954:Receptors, Dopamine; D011976:Receptors, Muscarinic; D010095:Oxotremorine; D000109:Acetylcholine; D004298:Dopamine