Magel2 is required for the leptin-induced depolarizing response in POMC neurons.

<p>Example of a LepRb^EGFP positive neuron identified for electrophysiological recordings using: A) infrared-differential interference contrast imaging (scale bar, 10 µm) and B) epifluorescence. C) Mean RMP of ARC LepRb+ neurons (<i>n</i>>50 of each genotype, values are means ± SEM). D) Current clamp recording of a LepRb^EGFP neuron showing the hyperpolarizing effect of 300 nM NPY. E) There was no difference in the magnitude of hyperpolarization between control and <i>Magel2</i>-null neurons treated with 300 nM NPY. F–H) Current clamp recordings of typical responses to 100 nM leptin in F) depolarizing neurons (ΔRMP>2 mV over baseline), and G) hyperpolarizing neurons (ΔRMP>2 mV below baseline). H) Changes in RMP with application of 100 nM leptin to ARC LepRb^EGFP neurons. Circles represent individually tested neurons. Depolarizing, hyperpolarizing, and unresponsive neurons were found in control slices, while only hyperpolarizing and unresponsive neurons were found in <i>Magel2</i>-null slices. Difference between genotypes is significant by Fishers Exact Test, <i>P</i><10⁻⁸. I) Mean RMP of ARC POMC^EGFP neurons (<i>n</i>>40 of each genotype, means ± SEM). J) Changes in RMP caused by application of 100 nM leptin to ARC POMC^EGFP neurons. Depolarizing responses were observed in control but not <i>Magel2</i>-null neurons. Difference between genotypes in the number of depolarizing neurons is significant by Fishers Exact Test, <i>P</i><10⁻⁸.