Figure 4.

Presynaptic modulation of excitatory synaptic input to POMC neurons. A, B, Hypocretin effects on the frequency of EPSCs are shown for a representative experiment (A) and summarized for 21 cells (B). C, D, mEPSCs detected in TTX. The mEPSC waveform (C) or cumulative distribution (D) is shown before and after hypocretin application. No apparent changes in mean EPSC waveform (in black), mean amplitude, or cumulative distribution of peak EPSC amplitude were observed. E, F, Bar graphs summarizing the actions of hypocretin on mean mEPSC amplitude (E) and frequency (F). G, Population bar graph depicting the reversible increase in EPSC frequency that follows hypocretin application in eight POMC cells loaded with 20 mm BAPTA. Hcrt, Hypocretin; Ctrl, control. *p < 0.05.