E2 increases the excitability of AVPV/PeN Kiss1 neurons. A and B, The spontaneous firing rate of Kiss1 neurons was increased in high-E2 vs low-E2 animals in the presence of ionic glutamatergic and GABAergic receptor blockers (10 μM CNQX, 50 μM AP-5, and 100 μM picrotoxin). C, A representative recording showing that E2-treated ARC Kiss1 neurons are silent in the presence of ionic glutamatergic and GABAergic receptor blockers. D, Summary of the effects E2 treatment on the spontaneous firing of AVPV/PeN and ARC Kiss1 neurons. *, P < .05; ***, P < .001, Student's t test.