Sabeluzole improves social recognition and antagonizes chlordiazepoxide's effect on habituation in the rat

The memory enhancing properties of sabeluzole were evaluated in two experimental paradigms in rats. First, we determined the protective action of sabeluzole against a chlordiazepoxide-induced impairment of habituation. Sabeluzole (5 or 25 mg/kg, SC) was administered 1 h before and chlordiazepoxide (20 mg/kg, SC) immediately after the acquisition session. In the retention session 72 h later, chlordiazepoxide-treated Animals displayed higher locomotor and rearing activities and this effect was blocked by pretreatment with sabeluzole. The results suggest that sabeluzole prevented the amnesic effect of chlordiazepoxide. The second paradigm was a social recognition test in which the behaviour toward a familiar or a novel conspecific was investigated. Time spent in social investigation and time spent sniffing of scent traces left on the floor was estimated during exposure of an adult to a juvenile male rat. Sabeluzole (25 mg/kg, SC) was injected into the adults immediately after the first exposure. Reexposure to the same or a novel juvenile was performed 120 min later. In contrast to control, sabeluzole-treated Animals showed a significant reduction in social investigation during the second exposure to the same juvenile. Time spent sniffing the floor was significantly decreased in sabeluzole-treated males. Since there was no effect on investigation of a novel juvenile, results suggest that sabeluzole-treated rats are able to remember longer the individual characteristics of juvenile rat obtained through olfactory cues.