RU 24969-induced locomotion in rats is mediated by 5-HT1A receptors

The locomotor response to RU 24969 (5-methoxy-3-(1,2,3,6-tetrahydropyridin-4-yl) 1H-indole; 10 mg/kg, s.c.), a preferential 5-HT(1B) receptor agonist, was investigated in the rat, using two novel 5-HT(1A) receptor antagonists, WAY-100635 (0.3 mg/kg and 1 mg/kg, s.c.) and SDZ 216-525 (0.3 mg/kg, s.c.), and the novel 5-HT(1B)/5-HT(1D) receptor antagonist, GR 127935 (1 mg/kg, s.c.). The antagonists per se did not alter spontaneous locomotion. Both selective 5-HT(1A) receptor antagonists blocked RU 24969-induced hyperlocomotion, whilst the 5-HT(1B) receptor antagonist was without effect. These results suggest that RU 24969-induced hyperlocomotion in the rat is mediated by 5-HT(1A) receptors.