Figure 3.

Properties of neuronal firing thresholds and derivatives of spiking. A, Proportion of neurons with indicated threshold ranges (= threshold at depolarization − threshold at hyperpolarization). Numerals right to columns are neuron numbers. B, Firing thresholds as a function of membrane potential. Examples of neurons with absolute threshold ranges ≥10 mV. Filled circles indicate thresholds at RMPs. C, Maximum rates of rise plotted against pretest membrane potentials. Light symbols are individual measurements from 9 dINs and 9 non-dINs. Dark circles with error bars are binned averages (every 10 mV between 0 and −100 mV). D, Thresholds at RMPs plotted against the firing reliability in swimming. Black lines and symbols are for non-dINs, and red lines and symbols are for dINs in A–D.