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 nicotin e treatment has chiefly been demonstrated by in vitro binding assays. Here, we report that up-regulation of nAChRs in CD-1 mice can be detec ted using a specific in vivo radioligand for nAChRs, [I-125]IPH. After 10 days of (-)-nicotine administration, male and female mice demonstr ated a significant elevation of [I-125]IPH binding in all brain region s studied. [I-125]IPH uptake also displayed significant gender differe nces with male animals showing a more pronounced increase in [I-125]IP H accumulation. Synapse 29: 116-118, 1998. (C) 1998 Wiley-Liss, Inc.