A, typical example of CeBF and [K+]o increases evoked by climbing fibre stimulation at 1, 2, 5, 7.5, 10 and 20 Hz for 60 s. Upper panel depicts recordings of CeBF increases as a percentage of the baseline value. Lower panel shows simultaneous [K+]o traces (mm). Bar (at bottom) indicates the duration of stimulation. B, CeBF and [K+]o increases plotted versus stimulation frequency (n = 5). Increases in CeBF are shown on the ordinate to the left as percentage increases of baseline and the maximal values to which [K+]o increased are shown on the ordinate to the right. The smooth curves represent sigmodial curve fitting. The dashed lines show the frequencies at which the half-maximum increase occurred (F½).