Attenuation of two distinct types of inhibitory inputs to CA1 pyramidal neurons by BDNF in the gramicidin perforated-patch method. A, Stimulation of the stratum pyramidal (SP stim.) and the stratum lacunosum-moleculare (SL-M stim.) produced distinct types of outward-directed IPSCs in the same CA1 pyramidal cell voltage-clamped at −50 mV. In this mode BDNF (100 ng/ml) also reduced both types of IPSCs. The representative traces are from the time points indicated in B. B, The typical time courses of reduction of the amplitude of IPSCs generated by stimulation of two sources, SP (open circles) and SL-M (solid circles). BDNF at 100 ng/ml (horizontal solid bar) silenced both types of inhibitory inputs. Data are plotted as the mean of eight IPSCs evoked by alternative stimulation of SP or SL-M in the same neuron.