Hydrogen sulfide decreases a slow rectifying potassium conductance in nucleus tractus solitarius neurons (1129.4)

Hydrogen Sulfide (H 2 S) is an endogenously produced gasotransmitter which has been shown to play a role within the central nervous system. Prior studies have shown that H 2 S has presynaptic effects on neurons of the nucleus tractus solitarius (NTS) through modulation of glutamate transmission. We have also recently demonstrated postsynaptic effects of H 2 S on the membrane potential of NTS neurons. The current study was undertaken to investigate the ion channels in NTS neurons modulated by H 2 S. Using whole cell voltage‐clamp recordings we found that H 2 S causes a decrease in current evoked in the depolarizing range of a slow voltage ramp indicative of modulation of the voltage activated potassium conductance I K . This conductance was found to decrease by a mean of 20.2 ± 2.5% (n=11) at the end of the ramp (10 mV) following application of 10 mM NaHS, a H 2 S donor, with all 11 neurons influenced in a similar manner. All cells demonstrated a partial to full recovery of this conductance after wash off of NaHS. The present work suggests that H 2 S controls the excitability of NTS neurons, at least in part through the modulation of the delayed rectifier potassium conductance, I K . Grant Funding Source : This work was supported by the Canadian Institutes for Health Research.