Effects of Protonophores on Membrane Electrical Characteristics in NG108-15 Cells

Studies were conducted to determine the effects of bath application of the protonophores carbonyl cyanide m-chlorophenylhydrazone (CCCP) and carbonyl cyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP) on membrane electrical characteristics of differentiated NG108-15 (neuroblastoma X glioma hybrid) cells. Membrane resting potential (V_m), input resistance (R_in) and electrically induced action potential generation were measured using intracellular micro-electrode techniques. Both compounds produced concentration-dependent depolarization rather than the hyperpolarization commonly found with other central mammalian neurons. CCCP and FCCP also reduced R_in and disrupted the generation of action potentials in a concentration-dependent manner. The contribution of the observed alterations to the in vivo toxicity of these compounds remains to be established.