Figure 10.

Activating LHA^Vgat+ neurons does not induce the intake of a bitter tastant, nor an unavoidable aversive stimulus, but it increases sucrose consumption. (A) Schematic of behavioral setup showing stimuli delivered at the central port. The water stimulus in the central port was replaced by an empty sipper, quinine, or airpuff. In all phases, head entry in the central port triggered the laser, except in the airpuff unavoidable condition, where the first lick delivered both the laser and the airpuff. Finally, the airpuff in the central port was replaced by sucrose 18%. (B) The number of opto-self-stimulations given for each stimulus. The VGAT-ChR2 mice performed more self-stimulations than WT, except during extinction sessions and when the airpuff was unavoidable. (C) The number of licks given to the central port. The licks in the central port decreased when an aversive stimulus was present, such as quinine or airpuffs. In contrast, a non-edible stimulus such as an empty sipper elicited more licks from VGAT-ChR2 mice (p < 0.05). Moreover, when sucrose 18% was in the central port, the VGAT-ChR2 group increased its consumption substantially compared with the WT. (D) The number of licks in the lateral port containing sucrose 18% during opto-self-stimulation. The intake of the lateral port of sucrose 3% is not shown because it was neglectable. Each dot and triangle represent a single individual. ^∧Denotes statistically significant difference (p < 0.0001) from WT. Unpaired Student's t-test. *p < 0.05 relative to the WT group. ^#p < 0.05 between sucrose 18% from other stimuli delivered at the central port. Two-way ANOVA followed by the Holm–Sidak test.