Fig. 10.
Combined effects of ACh and 5-HT on EGFP+ neurons. Recordings were made from a type 3 cell in lamina VIII in control (A) and conditions of ACh (B) and 5-HT (C). The current injections in A–C were the same as those shown in A. A: control recordings. A1: hyperpolarizing step current (1 s with 50 pA for each step, bottom traces) was injected into the cell. Voltage deflection (top traces) produced by the −50-pA step current was used to calculate Rin (540 MΩ). A2: repetitive firing (top trace) was evoked in the same cell by a 2-s ramp current (bottom trace). The Vth was measured from the 1st spike (−35.0 mV). B: recordings with bath application of 20 μM ACh. B1: the Rin (358 MΩ) was reduced by 182 MΩ and Ih was diminished. B2: in the same condition of ACh the Vth (−43.6 mV) of the 1st spike was hyperpolarized by 8.6 mV. C: recordings with bath application of 5-TH (20 μM) subsequently. C1: 5-HT increased the Rin (530 MΩ) by 172 MΩ from that measured in the condition with ACh. C2: Vth (−52.7 mV) was further hyperpolarized by 9.1 mV by 5-HT.