Effects of hippocampectomy on the development and recovery of a conditioned reflex to time in rats.

Experiments were carried out on rats to study the dynamics of recovery of a conditioned reflex to time after electrolytic lesioning of the dorsal hippocampus and the effects of hippocampectomy on the development of this response. Lesioning of the hippocampus deranged the restoration of a conditioned reflex to time which had been fixed before surgery. In conditions of limited hippocampal damage, the conditioned reflex to time recovered earlier than in sham-operated animals. Animals with more significant damage showed delays in the recovery of the response to time. After hippocampectomy without initial training, the conditioned reflex to time could not be developed regardless of the extent of damage to the hippocampus. This process was also not affected by doses of phenamine of 0.05 mg/kg.