Synaptic depression in principal neurons of the rat MNTB Synaptic depression in principal neurons of the rat MNTB. A, An example of EPSCs elicited by afferent fiber stimulation trains of 30 stimuli at 0.5 Hz. Voltage-clamp recordings were made at a holding potential of −80 mV in 2 mm [Ca]o and 1 mm[Mg]o. Synaptic depression in principal neurons of the rat MNTB. A, An example of EPSCs elicited by afferent fiber stimulation trains of 30 stimuli at 0.5 Hz. Voltage-clamp recordings were made at a holding potential of −80 mV in 2 mm [Ca]o and 1 mm[Mg]o. Note that the first EPSC in the train is the largest and that the onset of the EPSCs was ≈1.5 msec after the stimulus artifact. B, In the same cell as inA, EPSCs were elicited by 30 stimuli at 10 Hz.C, The peak EPSC amplitude of examples Aand B are plotted for 0.5 Hz (open symbols) and 10 Hz (closed symbols). These AMPA receptor-mediated EPSCs depressed from the initial amplitude (I0) to a new steady-state value (Iss), which was obtained from the steady-state value of an exponential fit (solid line; τ = 2.47 sec for 0.5 Hz and τ = 159 msec for 10 Hz). Henrique von Gersdorff et al. J. Neurosci. 1997;17:8137-8146 ©1997 by Society for Neuroscience