Figure 4.
Stimulating inhibitory neurons in the MnPO/OVLT reduces water consumption, but not food consumption. A, Normalized cumulative spout licks (mean ± SD, N = 7) during 60 min of water access in water-deprived VGAT-ires-creChR2+ mice. Stimulation (1 s on/2 s off, 20 Hz, 5 ms, 13 mW; in blue) was applied for the first 30 min of the water access period. *p < 0.05, **p < 0.01, ***p < 0.001 by post hoc t test with Bonferroni's correction. B, Normalized spout licks by water-deprived mice during the first 30 min of the 60 min access period. (***p < 0.001 by post hoc t test with Bonferroni's correction). C, Injection site in a VGAT-ires-CreChR2+ mouse in which the injection was lateral to the MnPO, and in which the animal had no response to optogenetic stimulation during water repletion after dehydration. Bregma level, −0.12 mm. Scale bars, 250 μm. D, Time course of cumulative water spout licks during a 1 h access period following overnight water deprivation for the mouse shown in C. E, Food consumed by food-deprived mice during the first 30 min of food access as a percentage of the total amount of food consumed in 60 min.