Fig. 4.
Effect of secretin on miniature IPSCs and postsynaptic GABAA receptor sensitivity of Purkinje cells.A, A typical experiment showing that secretin increased the frequency of GABAA-mediated miniature IPSCs. Secretin was added to the superfusion solution for 4 min. Two sets of traces at the time points indicated are shown on a fast time-base. In this cell, recovery from the effect of secretin took 35 min. B, Concentration–response curve of the effects of secretin on the frequency (left) and amplitude (right) of the miniature IPSCs. A clear dose-dependent effect was found in the frequency only. Numbers in theparentheses denote the number of cells tested.C, The postsynaptic sensitivity of GABAAreceptor of a Purkinje cell in the absence (left) or presence (right) of 30 nm secretin was compared. Small volumes (1 μl) of 0.1 mm GABA were applied directly to the bath at a fixed distance from the recorded cell.