[Interaction with cholinergic drugs in reversal of cycloheximide-induced amnesia by thyrotropin-releasing hormone and its analog DN-1417 in mice].
The reversal effect of drugs on experimental amnesia was studied using one-trial passive avoidance task in mice. Cycloheximide (120 mg/kg) given sc 30 min before the acquisition of avoidance response caused amnesia by showing short latency to enter from the safety compartment into the shocked compartment in the retention test conducted 24 hours later. In these cycloheximide-treated animals, physostigmine (0.1 mg/kg), thyrotropin-releasing hormone (TRH: 10-20 mg/kg) and DN-1417 (5-20 mg/kg) given sc 15-60 min before the retention test markedly prolonged response latency, indicating reversal of amnesia. The effects of all these drugs were almost completely antagonized by anticholinergic drug, scopolamine (0.4-10 mg/kg). Although physostigmine when administered in conjunction with TRH potentiated the reversal effect, there was no potentiation with DN-1417. Since these drugs did not affect test performance in the cycloheximide-treated mice which had experienced no foot-shock, it is unlikely that the amnesia-reversing effect of the drugs was a result of non-specific suppression on motor activity. These results suggest that cholinergic activation reverses cycloheximide-induced amnesia, and TRH and DN-1417, while they showed a difference in the action of potentiation with physostigmine, may also activate a retrieval process of memory by mediation of cholinergic mechanism.
D000647:Amnesia / Q000139:chemically induced; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D010275:Parasympathetic Nervous System / Q000187:drug effects; D010830:Physostigmine / Q000494:pharmacology; D011930:Reaction Time; D012601:Scopolamine / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*
D000927:Anticonvulsants; D013973:Thyrotropin-Releasing Hormone; D003513:Cycloheximide; C029762:DN 1417; D010830:Physostigmine; D012601:Scopolamine