[Sabeluzole and flunarizine in memory processes: animal studies]

The memory enhancing properties of sabeluzole nad flunarizine were evaluated in two experimental paradigms in male rats. First, we studied the protective action of both drugs against a chlordiazepoxide-induced impairment of habituation. Sabeluzole (5 or 25 mg/kg) or flunarizine (10 mg/kg) were administered sc 1 hr before and chlordiazepoxide (20 mg/kg) immediately after the acquisition session. In the retention session 72 hr later, chlordiazepoxide treated animals displayed higher locomotor and exploratory activities and this effect was blocked by pretreatment with sabeluzole or flunarizine. The results suggest that both drugs prevented amnesic effect of chlordiazepoxide. The second paradigm was the social memory test in which the time spent in social investigation behaviour toward a familiar or a novel juvenile conspecific was used to measure the duration of the memory that the animal forms of the juvenile. Sabeluzole (25 mg/kg) or flunarizine (3 mg/kg) were injected to the adults immediately after the initial exposure. Reexposure to the same or a novel juvenile was done 2 hr later. In contrast to controls, sabeluzole-treated animals showed a significant reduction in social investigation during reexposure to the same juvenile. 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 rats obtained through olfactory cues during a short social interaction. The time spent by adults treated with flunarizine in the investigation the same juvenile during reexposure was similar to that observed during the initial exposure. It means that flunarizine was ineffective in enhancing short-term olfactory memory.