Figure 3.

Stimulating excitatory neurons in the MnPO/OVLT cause water consumption. A, Experimental setup for testing optogenetic driving of drinking behavior. B, Raw data from lickometer showing onset and pattern of drinking during 1 min stimulation (10 Hz, 5 ms pulse, 11 mW). C, An injection site in mouse id224 (VGluT2-ires-Cre^ChR2+), in which the injection was lateral to the MnPO and the animal did not consume water during stimulation. Bregma level, +0.42 mm. Scale bars, 250 μm. MPA/LPO, Medial/lateral preoptic area. D, Total number of spout licks during a series of eight 1 min trials (i.e., 1 min on/1 min off). *p < 0.05. E, Solution preference assay (N = 7; ***p < 0.001 vs H₂O, ###p < 0.001 vs saline). Box-and-whisker plot reflects range, 25% and 75% range, and median.