Figure 9.

Blockade CRH1R(s) in the PVN lowers basal blood pressure and diminishes the firing activity of presympathetic neurons. A, Representative pulsatile arterial blood pressure traces following PVN microinjection (100 nl) with vehicle, different doses of Astressin (50, 100, 200 μm), and Astressin following systemic administration of hexamethonium. B, Grouped data demonstrating (left) the change in SBP and (right) mean arterial pressure (MAP) following the administration of vehicle and the different doses of Astressin into the PVN (n = 6 per group). C, PVN administration of Astressin (200 μm) before (n = 6) or after (n = 4) the systemic administration of hexamethonium (30 mg/kg, i.p.). p < 0.05; p < 0.01; two-way ANOVA followed by Tukey's post hoc test for vehicle versus Astressin (100 μm). ^†p < 0.05; ^††p < 0.05; two-way ANOVA followed by Tukey's post hoc test for vehicle versus Astressin (200 μm). Arrows indicate time of injection. D, Representative traces of basal GCaMP7s activity in three independent recordings obtained from RVLM-projecting neurons (left) before and (right) subsequent to delivery of Astressin (0.5 μm). E, Summary data showing mean changes in GCaMP7s transients (left) frequency and (right) amplitude evoked by Astressin administration (n = 7 cells from 3 animals). Error bars indicate SEM.