Effects of 5-HT2 receptor antagonist on cycloheximide-induced amnesia in mice.


A role played by serotonergic neuronal system in cycloheximide (CXM)-induced amnesia was studied in mice using a step-down passive avoidance task. CXM (30 mg/kg SC) given immediately after training caused impairment of memory. Nonselective serotonin (5-HT) antagonist methysergide and selective 5-HT2 antagonist ritanserin significantly attenuated impairment of memory caused by CXM. 5-HT1 antagonist (+/-)-pindolol had no effect on CXM-induced amnesia. The antiamnesic effect of ritanserin on CXM-induced amnesia was antagonized by 5-HT (ICV), but not by nonselective 5-HT agonist 5-methoxy-N,N-dimethyltryptamine and 5-HT1A selective agonist 8-hydroxy-2-(di-n-propylamino)tetralin at the dose level which did not cause the memory disruption. Scopolamine antagonized the antiamnesic effects of methysergide and ritanserin on CXM-induced amnesia. These results suggest that 5-HT2 receptors and cholinergic neuronal system may play an important role in memory formation.

Cite this paper

@article{Nabeshima1989EffectsO5, title={Effects of 5-HT2 receptor antagonist on cycloheximide-induced amnesia in mice.}, author={Toshitaka Nabeshima and Kunihiko Itoh and Koichiro Kawashima and Tsutomu Kameyama}, journal={Pharmacology, biochemistry, and behavior}, year={1989}, volume={32 3}, pages={787-90} }