[The effect of hippocampectomy on the acquisition and recovery of a conditioned reflex to time in rats].

The dynamics of time conditioning was studied before and after electrolytic lesions of the dorsal hippocampus in rats. Hippocampectomy disturbed the recovery of time conditioned reflex which was consolidated before surgery. The change depended on the extent of hippocampal lesion. In rats after the limited hippocampectomy the conditioned reflex recovered faster than in sham-operated animals. However, after more extensive lesions the process of conditioning recovery was delayed. In hippocampectomized animals without previous training the time conditioned reflex was not formed irrespective of the volume of brain lesion. Injection of amphetamine (0.05 mg/kg) was ineffective in this case.