Fig. 3.

Gain in fidelity of transmission by blocking NMDA receptors. A, Postsynaptic responses during a train of 100 Hz stimuli in MNTB neurons at different postnatal periods. In immature mice d-APV (50 μm) abolished aberrant firings and relieved action potentials from block, thereby making synaptic transmission accurate. Resting potentials were −69 mV (P7), −72 mV (P15), and −67 mV (P27). B, A similar effect of d-APV on postsynaptic responses at 35°C in a P7 mouse. Resting potential was −66 mV. C, Summary of the effects of d-APV on the fidelity of transmission at 100 Hz (n = 10–11) before (▴) and after (▵)d-APV application at 26–27°C. d-APV had no effects on synaptic fidelity in P27 mice.