Caffeine reversibly decreases mEPSC amplitude.

<p>(A) Recording of mEPSCs in whole-cell voltage-clamp in the presence of TTX (1 µM). Caffeine (20 mM) caused a clear reversible decrease in mEPSC size. The fast rise and exponential fall of synaptic currents was clear throughout recording (insets). (B) Amplitude histograms of events in A 200 seconds immediately before caffeine (black) and during the last 200 seconds of caffeine application (blue). (C) Average mEPSC amplitudes for seven cells before (black), during (blue), and after (red) caffeine application. (D) Normalized average diary plots of mEPSC frequency (top) and amplitude (bottom), n = 7. Bin size = 10 seconds. Each point is normalized to the average of 200 seconds of data recorded before drug application.