Effect of stopping test synaptic stimulation immediately after LFS on synaptic responses. (A) Sample waveforms and a typical time course for the synaptic responses in the S-EPSP (left panel) or A-PS (right panel) before and after LFS (1000 pulses at 2 Hz) when test synaptic stimulation was either delivered at 0.05 Hz throughout the experiment (filled circles) or stopped for the 20-min period from 0 to 20 min after the end of LFS (unfilled circles). The sample waveforms were taken at the times indicated as a and b in the time course figure. (B) Summarized time course for the change in the S-EPSP (left panel) or A-PS (right panel) induced by LFS (1000 pulses at 2 Hz) when test synaptic stimulation was either delivered throughout the experiment (filled circles, n = 6) or stopped for the 20-min period from 0 to 20 min after the end of LFS (unfilled circles, n = 6). The unfilled horizontal bar marks the stimulation-off period and the filled horizontal bar represents the delivery of LFS. In these time course figures, the ordinate shows the S-EPSP or A-PS expressed as a percentage of the averaged value measured during the 10-min period before the delivery of LFS. The symbols and bars represent the mean ± S.E.M.
