[Disordered long-term memory in mice as affected by azidothymidine]

An action of azidothymidine (AZT) on the acquisition of passive avoidance behaviour was studied in mice. Intraperitoneal administration of AZT (5-80 mg/kg) inhibited markedly the formation of passive avoidance behaviour. AZT had amnestic effect when administered 1 hour before learning, immediately after learning, 1 to 3 hours, but not 5 hours after learning. Administration of AZT 1 hour before learning had no influence on passive avoidance behaviour tested 24 hours later. The first signs of amnesia appeared 48 hours after learning and the effect was maximum during testing one week after learning. It is suggested that this effect of AZT may indicate the necessity of reverse transcription in the nervous cells for the consolidation of long-term memory.