Trpv1Reporter Mice Reveal Highly Restricted Brain Distribution and Functional Expression in Arteriolar Smooth Muscle Cells

• DOI: 10.1523/jneurosci.6451-10.2011
• Publication Date: 2011-03-30T17:30:22Z
• Authors: Daniel J. Cavanaugh; Alexander T. Chesler; Alexander C. Jackson; Yaron M. Sigal; Hiroki Yamanaka; Rebecca Grant; Dajan O'Donnell; Roger A. Nicoll; Nirao M. Shah; David Julius; Allan I. Basbaum
• Keywords: Nociceptor; Capsaicin; Calcium imaging; Premovement neuronal activity

The heat and capsaicin receptor, TRPV1, is required for the detection of painful by primary afferent pain fibers (nociceptors), but extent to which functional TRPV1 channels are expressed in CNS debated. Because previous evidence based primarily on indirect physiological responses capsaicin, here we genetically modified Trpv1 locus reveal, with excellent sensitivity specificity, distribution all neuronal non-neuronal tissues. In contrast reports widespread robust expression CNS, find that restricted nociceptors sensory ganglia, minimal a few discrete brain regions, most notably contiguous band cells within adjacent caudal hypothalamus. We confirm hypothalamic mouse using several complementary approaches, including situ hybridization, calcium imaging, electrophysiological recordings. Additional hybridization experiments rat, monkey, human demonstrate conserved across species. Outside subset arteriolar smooth muscle thermoregulatory Here, increases uptake induces vasoconstriction, an effect likely counteracts vasodilation produced activation TRPV1.