Figure 2.

OT selectively increases the frequency of mEPSCs. A, Representative current traces in TTX and GZ show that OT (1000 nm) increased the mEPSC frequency in an identified second-order medial NTS neuron (ST-EPSC latency = 7.70 ms with jitter = 163 μs). B, The frequency histogram of this OT-sensitive neuron demonstrates that increases in frequency occurred rapidly and were reversible after wash (bins 10 s). C, OT (gray) significantly shifted cumulative mEPSC frequencies to shorter interevent intervals (K–S test, p < 0.001). D, Normalized group averages for similarly tested OT-sensitive NTS neurons show that OT significantly increased mEPSC frequency beginning at 100 nm (n = 4–8 neurons/conc., *p < 0.05, ANOVA). These results are consistent with OT acting presynaptically to increase glutamate release onto OT-sensitive second-order NTS neurons.