Effects of BzATP on the amplitude, frequency and time-course of sEPSCs in rat LC neurons. A Representative recording of sEPSCs before, during and after a 10-min superfusion with BzATP (300 μM). Note the stability of the holding current in spite of the presence of BzATP. B Representative recordings of two sEPSCs of similar amplitude under control conditions (left panel) and in the presence of BzATP (right panel). The decay phases of the amplitudes were fitted according to a monoexponential function to calculate the offset time constants (τoff). There was no change of the offset time-constant 8–10 min after the application of BzATP, when compared with the control values (for the mean onset and offset time constants see the “Results” section). Mean ± S.E.M. of seven experiments. C Plot of the number of events against the amplitude (Ca) and inter-event interval (Cb) in the cell shown in A and B. Statistically significant shift by BzATP of the control plot of cumulative probability against the inter-event interval (Cb, inset). Change of the absolute amplitude (Da) and frequency (Db) of the sEPSCs before, 8–10 min after the application of BzATP, and a further 8–10 min of washout. Mean ± S.E.M. of seven experiments. #P < 0.05; statistically significant difference from the control value