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 μg) did not produce turning behavior. In rats pretreated with unilateral injections of the dopamine D
1-like/D
2-like receptor antagonist,
cis (Z) -flupentixol (10 pg), into the ventrolateral striatum and saline into the nucleus accumbens core of contralateral side, systemic injection of a mixture of dopamine D
1-like (SKF 38393, 3 mg/kg) and D
2-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 D
1-like/D
2-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 D
1-like/D
2-like receptor-mediated pivoting was suppressed by either baclofen (100 ng) or 2-hydroxysaclofen (2 pg) 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 D
1-like/D
2-like receptor-mediated pivoting. (J Oral Sci. 45, 185-192, 2003)
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