Methylphenidate Enhances NMDA-Receptor Response in Medial Prefrontal Cortex via Sigma-1 Receptor: A Novel Mechanism for Methylphenidate Action
Figure 3
MPH has no effect on non-NMDA-R current, but enhances NMDA-R current in pharmacologically-isolated cells.
(A) MPH (50 µM) produced no effect on non-NMDA-R current. Recordings of non-NMDA-R currents were performed in the presence of AP-5 (50 µM), TTX (1 µM) and BMI (20 µM), with holding potential of −70 mV. As seen, pressure-application of glutamate (100 µM) induced an inward non-NMDA-R current (left), and this current was unchanged when MPH was administered (right). P>0.05 for MPH vs. control, n = 7, paired t-test. (B) MPH (50 µM) enhanced NMDA-R current. Recordings of NMDA-R currents were performed in the presence of CNQX (20 µM), TTX (1 µM) and BMI (20 µM), with holding potential of −40 mV. As shown, pressure-application of NMDA (100 µM) induced an inward NMDA-R current (left), and this current was enhanced when MPH was applied (right). **P<0.01 vs. control, n = 10, paired t-test.