Figure 5. Electrophysiological effects of electrotonic coupling in individual s.o. interneurones.

Increased cell excitability due to electrotonic coupling. A, 12 sweeps are overlapped to show that depolarization of one interneurone increases the firing probability of the other cell. B, average of all traces, showing, at higher gain, the electrotonically mediated depolarization. C, spontaneous activity between two electrotonically coupled s.o. interneurones. The lower trace shows spontaneous EPSPs in one interneurone. Apparent spikelets, which are closely time-locked to a spike from the coupled cell, are summated onto what appears to be an underlying chemical EPSPs.