(A) Epifluorescence micrograph of brain slice with POMC neurons expressing ChR2-tdtomato. Blue circles: photostimulation sites; ARC: arcuate nucleus; 3V: third ventricle; D: dorsal; V: ventral.
(B) ChR2-mediated photostimulation of POMC neurons in brain slices from deprived mice in the presence or absence of NTX. Photostimulation of POMC neurons reduces fmEPSC unless performed in the presence of NTX.
(C) Subset of neurons in (B) subjected to AICAR after photostimulation. POMC neuron photostimulation in the absence of NTX (n = 5) rendered fmEPSC in AGRP neurons sensitive to AICAR, while those photostimulated in the presence of NTX (n = 5) were insensitive to AICAR, indicating that a POMC neuron-derived opioid, inactivates AMPK.
**P < 0.01. Data are represented as mean ± s.e.m.