Fig. 2.

LH GABA neurons project caudally to the locus coeruleus, where terminal stimulation elicits eating and evokes GABA receptor-mediated currents in nonnoradrenergic neurons. (A) Sagittal representative image of eYFP-expressing (green) fibers projecting from LH and TH staining (red). (B) Representative coronal section showing fluorescence of LH terminals in peri-LC and fiber placement. (C) Photostimulation of VGAT LH-peri-LC-ChR2 produces eating. (D) Photostimulation of LH-peri-LC produces GABA-A synaptic current blocked by picrotoxin. Inward currents were measured from Vhold = −88 mV. (E) Synaptically connected cells (blue) were all located medial to the LC. (F and G) Photostimulation of VGAT LC-ChR2-eYFP produces eating. *P < 0.05 post hoc comparison vs. null value.