Fig. 2.

Representative responses to bilateral inhibition of the NTS and CVLM during infusion of sodium nitroprusside (SNP). A: infusion of SNP throughout the protocol reduced AP below baroreceptor threshold and increased sympathetic nerve activity (SNA) and heart rate (HR). Inhibition of the NTS by bilateral microinjection of muscimol (Mus; at arrowheads) during infusion of SNP did not change SNA, HR, or AP. Inhibition of the NTS abolished the sympathoinhibitory response to phenyl biguanide (PBG; at arrowhead). Subsequent inhibition of CVLM by bilateral microinjection of Mus during infusion of SNP significantly raised SNA, HR, and AP. Ten-second windows of SNA at baseline (B), after Mus-NTS (C), and after Mus-CVLM (D) show the increase in splanchnic nerve burst frequency with each manipulation. bpm, Beats/minute; Int, integrated.