Binding of [125I]A-85380 (0.6 nM) was done in the presence of 100 nM αCtxMII to block binding to α6/α3* subtypes, and is shown in representative sections from four treatment groups: A, adult saline; B, adult nicotine; C; periadolescent saline; D, periadolescent nicotine; E, non-specific binding in the presence of 100 µM nicotine in an adjacent section. DLG, dorsal lateral geniculate nucleus; RSGb, retrosplenial granular cortex; SNC, substantia nigra, pars compacta; Sub, subiculum. Sections cut approximately −5.0 mm from bregma.