Fig 4. Tesofensine reduces the feeding behavior induced by the optogenetic activation of LH GABAergic neurons in lean Vgat-ChR2 mice.

A. Schematic of the open-loop task, where VGAT-ChR2 mice (n = 4) with a fiber implanted in their LH, were stimulated at 50Hz for 2 seconds with 4 seconds off in blocks of 5 minutes (blue). Mice could lick a sucrose solution (10%) from a sipper. B. Cumulative licks during the open-loop stimulation with tesofensine (Teso) 2mg/kg or saline solution (Sal) administered by subcutaneous injection 30 minutes before the task. The tesofensine group (gray) was placed in the task, but the laser was not stimulated. Note that the teso+laser group exhibited an attenuated feeding response elicited by stimulation of LH GABAergic neurons. C. Total licks during a session, with blue bars representing the blocks that were laser stimulated in the task. D. Stimulus-bound feeding is the fraction of licks given during the stimulation window (spanning from the first laser pulse to 2.5 seconds after), with each circle representing a different mouse. Data are presented as mean ± SEM, and the results were statistically significant (*p-value < 0.05 based on paired t-test value).