EFFECTS OF HUPERZINE-A ON NUCLEUS BASALIS MAGNOCELLULARIS LESION-INDUCED SPATIAL WORKING-MEMORY DEFICIT

AIM: To study the effects of huperzine A an nucleus basalis magnocellu laris (NBM) lesion-induced spatial working memory impairment. METHODS: A delayed-non-match-to-sample radial arm maze task was used to study spatial working memory. ?he choline acetyltransferase (ChAT) activity was determined by the conversion of [H-3]acetyl-CoA to [H-3]ACh. RESUL TS: Unilateral NBM lesion by kainic acid 0.02 mu mol impaired rat's ab ility to perform this working memory task as; evidenced by fewer corre ct choices after different delay intervals and more total errors to co mplete the task. This behavioral impairment associated with a decrease in the activity of ChAT by about 40% in the ipsilateral cerebral cort ex. Huperzine A (0.2 mg . kg(-1) ip 30 min before testing) ameliorated this spatial working memory impairment. Physostigmine (0.2 - 0.3 mg . kg(-1) ip 20 min before testing) also attenuated the NBM lesion-induc ed memory deficit. CONCLUSION: The integrity of NBM, is critical for s patial working memory processing, and this working memory impairment i nduced by NBM lesion can be ameliorated by huperzine A and physostigmi ne.