Fig. 1: OxtrPBN activation suppresses fluid but not food intake.
From: Oxytocin-receptor-expressing neurons in the parabrachial nucleus regulate fluid intake
a,b, TdTomato expression in PBN of Oxtr Cre/+::Ai14 reporter mice (n = 3; a) and adult expression of mCherry fluorescence in OxtrPBN neurons (b) following injection of AAV-DIO-mCherry in a 9-week-old Oxtr Cre/+ male mouse (n = 7). dl, dorsolateral; el, external lateral; scp, superior cerebellar peduncle. Scale bar represents 100 µm. c, Representative example of electrophysiological activity in an OxtrPBN neuron using cell-attached configuration. We observed increased spiking after application of the Oxtr agonist TGOT (0.2 μM), which was inhibited by coadministration of the Oxtr antagonist atosiban (1 μM; the same neuron) (n = 4 of 4 OxtrPBN neurons). d, Injection of AAV-DIO-hM3Dq:mCherry in OxtrPBN neurons. Gray and black triangles denote loxP and lox2722 sites, respectively. e–i, Acute OxtrPBN activation with CNO revealed no significant change in food intake at baseline or after 24 h of fasting (n = 7 per group; two-way repeated measures (RM) ANOVA; baseline food: interaction F(8,96) = 0.2901, P = 0.9678; 24-h fast: interaction F(8,96) = 1.143, P = 0.3424) (e); decreased water and NaCl consumption following 24-h dehydration in the presence of food (n = 7 per group; two-way RM ANOVA; NaCl: interaction F(8,96) = 12.63, P < 0.0001; water: interaction F(8,96) = 39.75, P < 0.0001) (f) and in the absence of food (n = 6 per group; two-way RM ANOVA; NaCl: interaction F(8,80) = 8.173, P < 0.0001; water: interaction F(8,80) = 22.31, P < 0.0001) (g); decreased water consumption at baseline (n = 7 per group; three-way mixed design ANOVA; NaCl: interaction F(2.875,34.501) = 1.593, P = 0.210; water: interaction F(2.099,25.183) = 4.464, P = 0.021) (h); and no significant change in Ensure or water intake following 24 h of caloric deprivation (n = 6 hM3Dq, 7 mCherry; two-way RM ANOVA; Ensure: interaction F(8,88) = 0.3809, P = 0.9282; water: interaction F(8,88) = 0.5037, P = 0.8505). Data are expressed as mean ± s.e.m. mCh, mCherry; veh, vehicle. ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05. See Supplementary Table 2 for statistical analyses.
