FIGURE 7.
Prominent TRPV1 and TRPV1-dependent Fos expression at astrocytes in the CVOs of adult mouse brain and hypothermia by central activation of TRPV1. The expression of TRPV1 is prominent at GFAP+ astrocytes in the CVOs (A–C). The i.c.v. infusion of the TRPV1 agonist resiniferatoxin at 500 ng/kg causes prominent Fos expression at astrocytes rather than neurons in the CVOs (D–F). AP, area postrema; GFAP, glial fibrillar acidic protein; OVLT, organum vasculosum of the lamina terminalis; SFO, subfornical organ. Scale bars = 50 μm. Quantitative analysis shows central infusion of resiniferatoxin induces significant Fos expression at astrocytes preferentially in the CVOs and at neurons in the CVOs and neighboring brain regions (G). The i.c.v. infusion of the TRPV1 agonist resiniferatoxin induces hypothermia in a dose-dependent manner in WT mice, but not in TRPV1 KO mice (H). **p < 0.01, ***p0.001 between WT and TRPV1 KO mice with unpaired Student’s t-test (G) or an ANOVA with Tukey’s post-hoc-test (H). Photographs and graphs are rearranged with permission from John Wiley & Sons [(A–G) Mannari et al., 2013] and Springer Nature [(H) Yoshida et al., 2016].