NaSal suppressed the current-evoked firing in GABAergic, but not in 5-HTergic, neurons of rat DRN.

<p>(A) Sample action potential trains in response to three depolarizing current steps (+20, 50, 80 pA; duration: 500 ms) in a 5-HTergic neuron and a GABAergic neuron following NaSal. The firing of the GABAergic neuron remained depressed by NaSal even its hyperpolarized membrane potential was adjusted back to the control level with a 20 pA current injection. RMPs indicated beside the traces. (B) Time courses of changes in firing rate of the same neurons in response to a +80 pA depolarizing current during NaSal application. (C) NaSal significantly suppressed input-output functions of current-evoked firing in GABAergic (<i>P</i> <0.01 relative to control, two-way RM-ANOVA), but not in 5-HTergic, neurons (<i>P</i> >0.05 relative to control, two-way RM-ANOVA). (D) Bar graph (upper panel) and trajectory plots (bottom panel) showing changes in firing rate of 5-HTergic and GABAergic neurons in response to a 60 pA depolarizing current re threshold following application of NaSal (two-way RM-ANOVA and one-way RM-ANOVA with Bonferroni correction). Sample sizes are indicated in inset. **<i>P <</i>0.01. Vertical line bars represent one standard error.