Effects of huperzine A on nucleus basalis magnocellularis lesion-induced spatial working memory deficit.

AIM: To study the effects of huperzine A on nucleus basalis magnocellularis (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. The choline acetyltransferase (ChAT) activity was determined by the conversion of [3H]acetyl-CoA to [3H]ACh. RESULTS: Unilateral NBM lesion by kainic acid 0.02 mumol impaired rat's ability to perform this working memory task as evidenced by fewer correct choices after different delay intervals and more total errors to complete the task. This behavioral impairment associated with a decrease in the activity of ChAT by about 40% in the ipsilateral cerebral cortex. Huperzine A (0.2 mg.kg-1 i.p. 30 min before testing) ameliorated this spatial working memory impairment. Physostigmine (0.2-0.3 mg.kg-1 i.p. 20 min before testing) also attenuated the NBM lesion-induced memory deficit. CONCLUSION: The integrity of NBM is critical for spatial working memory processing, and this working memory impairment induced by NBM lesion can be ameliorated by huperzine A and physostigmine.