Fig. 3

Chemogenetic inhibition of Glu^LHb neurons suppresses pruritogens and chronic pruritus-induced scratching behavior. A Schematic diagram of bilateral injection of AAV-CaMKIIα-hM4Di-mCherry or AAV-CaMKIIα-mCherry into the LHb. B Schematic diagram of the experimental design. C Left: Representative histological images and summary data for the percentage of mCherry⁺ neurons which co-localize with anti-Glutamate in the LHb. (n = 3 sections per animal from 4 mice). Scale bars, 200 μm and 50 μm. D Schematic showing whole-cell recording of hM4Di-mCherry⁺ cells in acute brain slices. E Effect of bath application of 10 µM CNO on the membrane potential and action potentials of a hM4Di⁺ neuron (top) or a mCherry⁺ neuron (bottom) in the LHb. F, G Chemogenetic inhibition of Glu^LHb neurons significantly impaired scratching induced by intradermal injection of histamine (F) and chloroquine (G) into the nape. (hM4Di group, n = 6 mice; mCherry group, n = 8 mice). H Effects of chemogenetic inhibition of Glu^LHb neurons on spontaneous scratching behavior produced by AEW treatment on the 7th day. I Chemogenetic manipulation of Glu^LHb neurons had no effect on the motor ability in rotarod test. Significance was assessed by two-way ANOVA with Bonferroni’s multiple comparisons test in (F-H) and Mann-Whitney U test in (I), *p < 0.05, ****p < 0.0001, not significant (ns). All data were shown as mean ± SEM