Effects of nicotinic agonists on the NMDA receptor.

The cholinergic nicotinic agonists (-)nicotine and lobeline were observed to partially inhibit whole-cell N-methyl-D-aspartate (NMDA)-induced responses in rat cortical neurons in culture. In addition we found that (-)nicotine, (+)nicotine, and lobeline, but not the nicotine metabolite (-)cotinine nor acetylcholine, were able to displace [3H]dizocilpine ([3H]MK 801) binding in well-washed membranes obtained from rat brain. These results show that certain nicotinic agonists can interact with the NMDA receptor and block its function.