Effect of the 6-OHDA lesion on α6β2* nAChRs and α4β2* nAChRs in rat striatum. 125I-Epibatidine binding in the presence of the α6β2* nAChR antagonist α-CtxMII was used to identify α4β2* nAChRs, while 125I-α-CtxMII was used to detect α6β2* nAChRs in striatum. The concentrations of 125I-α-CtxMII and 125I-epibatidine were 0.5 nM and 0.015 nM, respectively. Values represent the mean ± SEM of 8 rats 6-OHDA-lesioned rats not treated with nAChR drugs.