Figure 2.

Action potential duration and discharge rate characteristics of cocaine-responsive neurons. A, Scatter plot of discharge rate versus action potential duration. Dotted line placed at 10 Hz on the x-axis demarks slow-firing from fast-firing neurons. Dotted line placed at 2.2 ms on the y-axis demarks short-duration from long-duration action potentials. Neither cocaine-excited nor cocaine-inhibited neurons form distinguishable clusters. B, C, Frequency distribution and mean action potential duration. Mean action potential duration is shorter in excited neurons than inhibited neurons, but their distributions overlap. D, Proportion of responsive neurons grouped in 10th percentiles. The dotted line placed at 82% shows the population percentage of responders. No differences are observed across the percentiles. E, Proportions of inhibited and excited neurons grouped in 10th percentiles. The proportions of responders are similar across different firing rates. Error bars are SEM; *p < 0.05.