Effects of the beta-carboline FG 7142 on saccharin preference and quinine aversion in water-deprived rats.

Three groups of water-deprived male rats were given the choice of 0.05% sodium saccharin solution and water; 0.0005% quinine solution and water; water in both containers. N'-Methyl-beta-carboline-3-carboxamide (FG 7142), a benzodiazepine receptor inverse agonist, dose-dependently (2.5-10 mg X kg-1 i.p.) reduced intake of fluid in each group. The saccharin-choice group were most sensitive, showing a significant reduction at 2.5 mg X kg-1. Preference for the saccharin solution was reduced by FG 7142 but it did not increase aversion to the quinine solution. Hence, FG 7142 did not generally increase the rejection of flavoured solutions in a two-bottle test. A previously proposed "proconflict" effect of FG 7142 is discussed, in the light of these results.