Fig. 2.

Time course of the up-regulation of both cytisine-sensitive and cytisine-resistant components of [¹²⁵I]epibatidine binding in hippocampus and diencephalon cultures. Binding was measured in total membranes prepared from hippocampus and diencephalon cultures at 0, 24, and 96 h for untreated neurons and neurons treated with 1 μM nicotine. Nonspecific binding was determined by using 100 μM cytisine. Results are expressed as specific [¹²⁵I]epibatidine binding ± S.E.M. in fmol/mg protein. The effects of nicotine treatment on cytisine-sensitive (●) and cytisine-resistant (○) components in [¹²⁵I]epibatidine binding for hippocampus cultures (A) and diencephalon cultures (B) are shown. Significant differences from control untreated neurons were calculated by using one-way ANOVA, followed by a Student-Newman-Keuls post hoc analysis. *, p < 0.05.