Figure 4.

Leptin inhibits midbrain LepR neurons. Electrophysiological recording were performed on LepR neurons identified by tdTomato (red) expression in VTA brain sections of LIC::Ai9 mice. In total, 16 out of 34 neurons responded to leptin. Representative images showing VTA brain sections with one LepR neuron identified for recording (A, arrow), immunostaining of injected biocytin during recording (B, blue), immunostaining of TH (C, green) and the merged (D). A representative recording trace showing changes in actual firing frequency (E) and the histogram of firing frequency (F) in response to leptin and washout. G, Summary of firing frequency changes in response to leptin of all neurons that responded to leptin. Scale bars, 100 μm.