A, Synaptic response induced in an SGI neuron in an adult animal by stimulation of the LSO in control solution (1), after application of 10μm Bic (2), after application of 10μm Bic plus 50 μm d-APV (3), and after washing out d-APV (4). Stimulus strength was 200 μA. B, Synaptic response induced in an SGI neuron in a young animal by stimulation of LSO after application of 10 μm Bic (1), after application of 10 μm Bic plus 50 μm d-APV (2), and after washing out d-APV (3). Stimulation strength was 100 μA. C, Synaptic response induced in an SGI neuron by stimulation of LSO in control solution (1) and after application of 10 μm Bic (2). The intracellular solution contained 30 mm BAPTA. Stimulus strength is given at right.