Dose-Related Nicotine Effects on CNS Binding and Behavior
Repeated nicotine exposures increase both central nicotinic receptor numbers and the behavioral stimulant effect of nicotine. In the present experiments, the behavioral effects of graded doses of nicotine (0.1 to 1.6 mg/kg, s.c.) were observed in photocell activity cages both before and after the rats were given five daily injections of 0.2 mg/kg nicotine in their home cages. Comparing the behavioral response after five days of exposure to the response prior to exposure revealed an upward shift in the dose-response curve (Fig. 1).