Fig. 4

Presynaptic modulation of LPB-A7 EPSCs by μ−opioid receptors. a. Representative experiment showing that the amplitude of LPB-A7 EPSCs was attenuated by DAMGO, and the effect was reversed by subsequent application of naloxone. b. Summarized results of the experiments shown in a. The amplitude of the EPSCs was normalized to the averaged value of the baseline recording (see dotted line). c. Representative experiment showing the effect of DAMGO on the PPR of LPB-A7 EPSCs. The upper traces are overlays of raw data traces (black: before and gray: after DAMGO application); note that DAMGO attenuated EPSCs as shown above. The lower traces show normalization of the response evoked by the first pulse of the two traces shown above and reveal an increase in the PPR by DAMGO. d. Summarized results of the experiments shown in c. The dotted lines are the results of individual experiments and the symbol line and vertical line are the mean and standard error, respectively. Asterisks mark significance at p < 0.01