Ai, neonatal P5 neurone: focal application of 100 μm GABA evoked membrane depolarization and multiple, adapting, action potential discharge. The excitatory response is inhibited by 10 μm bicuculline. Aii, GABA-evoked responses recorded from neurones in an adult, in situ ganglion preparation. The GABA-evoked depolarization is inhibited by bicuculline (10 μm). B, neonatal P5 neurone: conductance increase is associated with the GABA-evoked response. Cell input resistance was monitored by injecting −0.1 nA, 50 ms current pulses at 2 Hz.