Electroacupuncture ameliorates visceral hypersensitivity and negative emotions by regulating paraventricular hypothalamic nucleus and colonic corticotropin-releasing factor signaling

Figure 5 Corticotropin-releasing factor-ergic neurons of the paraventricular hypothalamic nucleus may regulate negative emotions and visceral hypersensitivity through colonic corticotropin-releasing factor-mast cell/transient potential receptor vanilloid type 1 pathway. A: Viruses (red fluorescence) were expressed on paraventricular hypothalamic nucleus (PVNs). Scale bar, 249 μm; B: Injection of the chemogenetically inhibited virus rAAV-CRH-hM4D(Gi)-mCherry-WPREs into bilateral PVNs and intraperitoneal injection of saline/clozapine-N-oxide (CNO) 21 days later; C: Statistical graph of saline injections in mice in the colorectal dilatation test; D: Paths travelled by mice in the open-field test; E: Statistical graphs of distance in center and time in center by mice in the open-field test; F: Detection of the mast cell (MC) degranulation rate in the mouse colon by toluidine blue staining in each group. Black arrows represent steady state MCs, orange arrows represent degranulated MCs. Scale bar, 50 μm; G: Statistical graphs of the MC degranulation rate; H: Representative image of the Western blot of corticotropin-releasing factor-receptor 1 (CRF-R1), mast cell tryptase (MCT) and transient potential receptor vanilloid type 1 (TRPV1) in mice colons were detected by Western blot; I: Statistical graph of the relative expression levels of CRF-R1; J: Statistical graph of the relative expression levels of MCT; K: Statistical graph of the relative expression levels of TRPV1; Each group n = 6, model + hM4Di + saline group vs normal + hM4Di + saline group, model + hM4Di + CNO group vs model + hM4Di + saline group; ^aP < 0.05, ^bP < 0.01; CRF: Corticotropin-releasing factor; PVN: Paraventricular hypothalamic nucleus; MC: Mast cell; TRPV1: Transient potential receptor vanilloid type 1; CNO: Clozapine-N-oxide; CRF-R1: Corticotropin-releasing factor-receptor 1; MCT: Mast cell tryptase.