H2S SFO Data Analysis

Data summarizing every recording for current clamp and rheobase analyse

miSFOH2S for plos paper

Raw data for blood pressure recording

Hydrogen sulfide depolarizes neurons in a concentration-dependent manner.

<p>(A) Current clamp recording illustrating the concentration dependent effects of 4 different concentrations of NaHS (red bars indicate time of application) in a single SFO neuron. (B) Scatter plot indicating the membrane potential changes for all neurons recorded. Black bars indicate mean ± SEM. (C) NaHS concentration curve illustrating proportion of responding neurons at each concentration, EC₅₀ = 35.6 µM.</p

Hydrogen sulfide depolarizes SFO neurons.

<p>Current clamp recordings from 2 SFO neurons demonstrating depolarizing effects of 1 mM NaHS (red bars indicate time of application). There was no difference in the depolarizing response observed in neurons that (A) fired spontaneously or (B) cells that were quiescent. In both cases there is a rapid-onset depolarization, followed by a recovery to baseline after return to vehicle aCSF.</p

Hydrogen sulfide increases the excitability of SFO neurons.

<p>An analysis of rheobase and action potential firing frequency revealed an increase in excitability. (A) Current clamp trace with red bar indicating application of NaHS (1 mM), and blue bars (α and β) indicate periods when current injection protocol was performed. (B) The middle panel shows the current injection protocols for 2X and 3X rheobase steps, and 0–200 and 0–500 pA ramps, while the spike patterns induced are shown for the control (left panel, α) and NaHS (right panel, β) conditions. Bar graphs displaying the mean number of action potentials before (black) and during (grey) NaHS application for the current step (C) and ramp (D) protocols. Note the increase in action potential number in response to NaHS in all 4 cases. *p<0.05, paired t test.</p

Primer sets used for RT-PCR analysis.

<p>Primer sets used for RT-PCR analysis.</p

Hydrogen sulfide microinjection into the SFO increases BP.

<p>Individual microinjection locations in SFO (Blue circle) and non-SFO sites (red squares) are illustrated in the schematic (A). The photomicrograph (B) shows one of the SFO microinjection sites (scale bar: 100 µm) C) Normalized mean (±SEM) BP trace (<i>i</i>) and summary graph (ii) illustrating BP change in response to NaHS (5 nmol) injection (arrow) into SFO (blue, n = 5), non-SFO (red, n = 4), or ventricle (green, n = 5). D) Normalized mean HR trace (<i>i</i>) and summary graph (ii) illustrating HR change in response to NaHS (5 nmol) injection (arrow). E) Bar graph illustrating dose-response relationship showing NaHS injections of 100 pmol (boxed), 500 pmol (white), 1 nmol (crossed), 5 nmol (solid), 10 nmol (dashed). Significant differences are indicated by asterisks, *p<0.05. Error bars denote SEM.</p