Fig. 8.
Dendritic plateau activation during different patterns of synaptic input. A: instantaneous firing rate vs. time for a medium-threshold motoneuron in response to excitation alone (black trace) and to excitation plus uniformly distributed inhibition of a constant mean level (blue trace), push-pull inhibition (red trace), and proportional inhibition (green trace). B: peak dendritic voltage (Vm) for excitation and different patterns of inhibition. C: firing rate vs. peak dendritic voltage. D–F: same as A–C, only for proximal inhibition. Different regions of the rate vs. dendritic voltage relations in C and F are region 1, during the initial activation of the plateau; region 2, during the period when the plateau depolarization is fairly stable; and region 3, during plateau deactivation. The dashed black line in C and F is the best linear fit to the firing rate vs. dendritic depolarization relation over region 2, for excitation alone.