Modulation of glutamatergic transmission does not affect the electrophysiological effect induced by inhibition of mitochondrial complex I, although it reduces the action of a complex II inhibitor. A, The glutamate transporter blocker dl-TBOA (10 μm), bath applied before and during the application of 0.1 and 1 μm rotenone, did not prevent the rotenone-induced reduction of the field potential amplitude. B, The preincubation with the NMDA receptor antagonists MK-801, memantine, and APV did not prevent the effect of rotenone. C, The NMDA and AMPA receptor antagonists APV and CNQX did not affect the rotenone-dependent membrane depolarization. D, The NMDA receptor antagonists MK-801 or memantine significantly reduced the electrophysiological effect of 3-NP, an inhibitor of mitochondrial complex II, on the field potential amplitude.