Targeted deletion of neurokinin-1 receptor expressing nucleus tractus solitarii neurons precludes somatosensory depression of arterial baroreceptor-heart rate reflex

Abstract

Neurokinin-1 receptor (NK1-R) expressing neurons are densely distributed throughout the nucleus tractus solitarii (NTS). However, their fundamental role in arterial baroreflex function remains debated. Previously, our group has shown that activation of contraction-sensitive somatic afferents evoke substance P (SP) release in the NTS and resets the arterial baroreflex via activation of a GABAergic NTS circuit. Based on these findings, we hypothesized that modulation of arterial baroreflex function by somatic afferents is mediated by NK1-R dependent inhibition of barosensitive NTS circuits. In the present study, SP-conjugated saporin toxin (SP-SAP) was used to ablate NK1-R expressing NTS neuro..