The nicotinic acetylcholine receptor antagonist mecamylamine does not block the effects of CPF or CPO on mitochondrial transport or dynamics. Various concentrations of mecamylamine were coincubated with 1.0 μM CPF or 0.005 μM CPO for 24 h. The results show that the axonal transport deficits (A and D) and increased mitochondrial length (B and E) induced by CPF and CPO, respectively, persisted in the presence of mecamylamine. The nonsignificant decreases in mitochondrial number associated with CPF (C) were also not antagonized, whereas the effects on the CPO-related effect on mitochondrial number (F) were less clear. Mecamylamine alone was not associated with significant effects on mitochondrial transport or length (A and B, right); however, it was associated with significant increases in number (C, right). Data are presented as mean (% control) ± S.E.M. *, significantly different (p < 0.05) from control; +, p < 0.09 versus control.