Simultaneous activation of the α1A-, α1B- and α1D-adrenoceptor subtypes in the nucleus accumbens reduces accumbal dopamine efflux in freely moving rats. Issue 1 (February 2015)

• Record Type: Journal Article
• Authors: Aono, Yuri; Taguchi, Hiroko; Saigusa, Tadashi; Uchida, Takuya; Takada, Koji; Takiguchi, Hatakazu; Shirakawa, Tetsuo; Shimizu, Noriyoshi; Koshikawa, Noriaki; Cools, Alexander R.
• Is Part Of: Behavioural pharmacology. Volume 26:Issue 1/2(2015)
• Publication Date: 2015-02
• Subjects: dopamine -- microdialysis -- nucleus accumbens -- rat -- α1A-adrenoceptor -- α1B-adrenoceptor -- α1D-adrenoceptor; Psychopharmacology -- Periodicals; Nervous System -- drug effects -- Periodicals; Behavior -- drug effects -- Periodicals; 615.78
• DOI: 10.1097/FBP.0000000000000113
• Languages: English
• ISSNs: 0955-8810

Abstract

Abstract : Intra-accumbal infusion of the α1 -adrenergic agonist methoxamine, which has comparable affinity for α1A -, α1B - and α1D -adrenoceptor subtypes, fails to alter noradrenaline efflux but reduces dopamine efflux in the nucleus accumbens of rats. In-vivo microdialysis experiments were carried out to analyse the putative contribution of α1A -, α1B - and α1D -adrenoceptor subtypes to the methoxamine-induced decrease in accumbal dopamine efflux in freely moving rats. The drugs used were dissolved in the infusion medium and administered locally through a dialysis membrane. Intra-accumbal infusions of the α1A -adrenoceptor antagonist 5-methylurapidil (6 pmol), the α1B -adrenoceptor antagonist cyclazosin (0.6 and 6 pmol) and the α1D -adrenoceptor antagonist BMY 7378 (0.6 pmol) did not alter accumbal efflux of noradrenaline or dopamine: pretreatment with each of these α1 -adrenoceptor subtype-selective antagonists counteracted the methoxamine (24 pmol)-induced decrease in accumbal dopamine efflux. Doses indicated are the total amount of drug administered over a 60-min infusion period. These results clearly suggest that the α1A -, α1B - and α1D -adrenoceptor subtypes in the nucleus accumbens mediate the α1 -adrenergic agonist methoxamine-induced decrease in accumbal dopamine efflux. The present study also provides in-vivo neurochemical evidence indicating that concomitant, but not separate, activation of the α1A -, α1B - and α1D -adrenoceptors in the nucleus accumbens is required for α1 -adrenergic inhibition of accumbal dopaminergic activity.