Direct ChR2 activation of Kiss1ARC neurons. A, Photomicrograph showing a recording pipette (outlined by white lines) patched onto an ARC Kiss1-ChR2:YFP cell. Scale bar, 20 μm. B, Whole-cell voltage clamp recording (Vh = −60 mV) of light-evoked inward currents with LED intensities increasing from 33 to 330 μW. C, Whole-cell current clamp recording of depolarizations/action potentials induced by 1-Hz photo-stimulation (intensity, 660 μW). Blue bar above recording indicates LED stimulus. D, Representative gel illustrating Kiss1 mRNA expression in ChR2:YFP recorded cells (Rec Cells). RNA extracted from the medial basal hypothalamic tissue was included as positive (+, with RT) and negative (−, without RT) controls. MM, molecular marker.