Fig. 5. AuIB blocks nicotine-stimulated norepinephrine, but not dopamine, release. A, AuIB blocks norepinephrine release from rat hippocampal synaptosomes. In contrast, α-CTx MII (α3β2-selective), α-CTx ImI (α7-selective), and α-CTx MI (α1βγδ-selective) all fail to block release. B,Conversely, α-CTx MII, but not α-CTx AuIB, α-CTx ImI, or α-CTx MI, blocks dopamine release from rat striatal synaptosomes. *p ≤ 0.001. Data are from 3–10 experiments with three to six replicates within each experiment. Norepinephrine release: 1 μm AuIB, p = 0.001; 5 μm AuIB, p < 0.001; MII,p = 0.75; ImI, p = 0.64; MI,p = 0.5. Dopamine release: 1 μm AuIB,p = 0.93; 5 μm AuIB,p = 0.68; MII, p < 0.001; ImI,p = 0.24; MI, p = 0.85.