Fig. 9.

A, Interneuronal spiking was elicited by injecting currents that simulate EPSCs generated by 50 independent afferent fibers firing at 5 Hz. The current injections simulated synapses that have only AMPARs (top), only KARs (middle), or AMPARs and KARs (bottom), all examined in the same cell. The simulated responses mediated by AMPARs elicited less spiking than did the responses simulating KARs, and the responses simulating both AMPARs and KARs generated the most spiking. B, The results from the simulations in seven cells are shown. C, The CV of the interspike interval, an assay for rhythmicity, indicated that KARs elicit more rhythmic spiking than AMPARs in six of seven cells, resulting in significantly more rhythmic firing when the whole population of cells was considered. In contrast, the CV of the interspike interval for synapses with both AMPARs and KARs was more variable and did not elicit significantly more rhythmic firing than synapses with either AMPARs or KARs.