Figure 3.

Chemogenetic manipulation of KOR^Cre neurons in the ARC produced increased levels of circulating PRL, transient CA and LS, mimicking effects of RS in female mice. (A) Representative images from KOR^Cre female mice expressing Gi-DREADD (hM4D(Gi)-mCherry) demonstrating expression of hM4D(Gi)-mCherry (red) in the ARC. Scale bars, 100 μm. (B) Concentration of PRL determined from serum collected 30 min after intraperitoneal administration of CNO at 5 mg/kg or vehicle, 4 weeks after stereotaxic administration of AAV8-hSyn-DIO-hM4D(Gi)-mCherry (100 nl) in the ARC from KOR^Cre or KOR^WT female mice. (C and D) Tactile frequency of response at baseline (−1) was collected right before injection of AAV8-hSyn-DIO-hM4D(Gi)-mCherry (100 nl) in the ARC of KOR^Cre or KOR^WT female mice. Four weeks after stereotaxic surgery, tactile frequency of response at baseline (0) was collected followed by three consecutive days of intraperitoneal administration of CNO at 5 mg/kg or vehicle. CA was assessed on indicated days after the first injection over a time course of 16 days (C and D). On Day 16, baseline (0) response was collected, followed by inhalational exposure of UMB (0.01 M/500 µl, each) with measurements collected hourly for 5 h (E, heterozygous and F, wild-type mice). Data are presented as mean ± SEM and analysed using one-way ANOVA followed by Tukey’s (B) or two-way ANOVA followed by Sidak’s (E and F) multiple comparison tests with *P < 0.05 (n = 5–7). Details of statistical analysis are found in Supplementary Table 1.