Fig. 1.

Genistein, an inhibitor of PTKs, suppresses GABA_A receptor-mediated currents in a cultured spinal dorsal horn neuron. A, Genistein (100 μm) applied in the bath medium inhibited currents evoked by pressure application of GABA (100 μm) from a micropipette whose tip was positioned within 50 μm of the neuron. Currents were recorded under whole-cell configuration at a holding membrane potential of −60 mV in all figures, unless specifically indicated otherwise. B, Genistein reduced the slope conductance but not the reversal potential of the GABA currents in the same neuron. On the left are individual current traces evoked at membrane potentials from −80 to +60 with a step of 20 mV in the absence (○) and presence (•) of genistein (100 μm) in the bath medium. On the right are theI–V curves constructed from recordings shown on theleft.