Fig. 8.

Depression of the complex PSP in a motor neuron but no change in firing of LE sensory neurons during habituation training. A, Records from a representative experiment.B, Average shape of the complex PSP and pattern of firing of LE cells on trials 1 and 5 in 20 experiments like the one shown in A. In some experiments the tap was not within the receptive field of the LE cell, there were problems with the PSP recording in the motor cell, or one cell was lost during habituation, in which case there were data from only one cell. The PSP area in each 50 msec interval has been normalized to the total area on trial 1 in each experiment (the average value on trial 1 was 6658 mVmsec). The average spike frequency in each 50 msec interval was calculated as the total number of spikes in that interval divided by (0.05 ×N). Time 0.0 for both the PSP and spike frequency histograms is the time that the PSP first exceeded a detection threshold, which did not always include the earliest part of the PSP. The horizontal bar below the x-axis represents the approximate duration of the plateau of the tap.