Muscarinic agonist binding in rat brain following chronic nicotine treatment.

Carbamylcholine binding was determined from competition experiments with [3H] quinuclidinyl benzilate in the rat brain chronically treated with nicotine. The nicotine group exhibited about two-fold lower affinity for the agonist binding toward a high-affinity site (or state) in the cerebral cortex, as compared with the control group. However, no alteration in the agonist binding was observed in the hypothalamus/thalamus and brainstem after chronic nicotine treatment.