GABA(A) receptors in the nucleus accumbens core modulate turning behavior induced by dopamine receptor stimulation.

Abstract

The role of GABA(A) and GABA(B) receptors in the core of the nucleus accumbens in turning behavior of rats was investigated. Unilateral injections into the core of the nucleus accumbens of the GABA(A) receptor agonist (muscimol, 50 ng) and antagonist (bicuculline, 200 ng), and the GABA(B) receptor agonist (baclofen, 100 ng) and antagonist (2-hydroxysaclofen, 2 microg) did not produce turning behavior. In rats pretreated with unilateral injections of the dopamine D1-like/D2-like receptor antagonist, cis(Z)-flupentixol (10 microg), into the ventrolateral striatum and saline into the nucleus accumbens core of contralateral side, systemic injection of a mixture of dopamine D1-like (SKF 38393, 3 mg/kg) and D2-like (quinpirole, 1 mg/kg) receptor agonists has been found to elicit contraversive pivoting, namely pivoting away from the side of the core injection. This dopamine D1-like/D2-like receptor-mediated pivoting was significantly inhibited by injections into the core of the nucleus accumbens of muscimol (50 ng), but not bicuculline (200 ng). In contrast, the dopamine D1-like/D2-like receptor-mediated pivoting was suppressed by either baclofen (100 ng) or 2-hydroxysaclofen (2 microg) injected into the nucleus accumbens core. It is therefore concluded that neither GABA(A) nor GABA(B) receptor stimulation in the core of the nucleus accumbens produces turning behavior, and that GABA(A), but not GABA(B), receptors in the nucleus accumbens core may modulate dopamine D1-like/D2-like receptor-mediated pivoting.