Nicotine induced up-regulation of nicotinic receptors in CD-1 mice demonstrated with an in vivo radiotracer: Gender differences

Up‐regulation of brain nicotinic receptors (nAChRs) by chronic nicotine treatment has chiefly been demonstrated by in vitro binding assays. Here, we report that up‐regulation of nAChRs in CD‐1 mice can be detected using a specific in vivo radioligand for nAChRs, [125I]IPH. After 10 days of (−)‐nicotine administration, male and female mice demonstrated a significant elevation of [125I]IPH binding in all brain regions studied. [125I]lPH uptake also displayed significant gender differences with male animals showing a more pronounced increase in [125I]IPH accumulation. Synapse 29: 116–118, 1998. © 1998 Wiley‐Liss, Inc.