Dorsal hippocampal lesion abolishes the response to FG-7142 in the rat.

The effects of the anxiogenic beta-carboline FG-7142 (15 mg/kg IP) on exploratory locomotor activity were assessed in rats with sham or ibotenic acid (IA) lesions of the dorsal or ventral hippocampus. FG-7142 reduced exploratory activity similarly in control animals as well as in those with IA lesions of the ventral hippocampus. In contrast, FG-7142 had no effect on rats with dorsal hippocampal lesions. The results suggest that the dorsal hippocampus plays a unique role in FG-7142-mediated attenuation of locomotor exploration. Other studies suggest that serotonergic systems may mediate these properties of FG-7142.