Acetylcholine increased postsynaptic currents (PSCs) in starburst amacrine cells (SACs). (A) Schematic diagram showing a cross-section of the retina. ON or OFF SACs labeled by GFP (green) were targeted. ON and OFF SACs were identified by the location of their soma. BC, bipolar cell; HC, horizontal cell; GC, ganglion cell; INL, inner nuclear layer; IPL, inner plexiform layer; a, sublamina a; b, sublamina b; GCL, ganglion cell layer. (B and D) Effects of ACh in an ON SAC (B) and OFF SAC (D). The thick black bar above the trace shows the timing of the ACh application. Thin black bars show the analysis time windows (20 s) of PSCs. These analysis time windows were set before (Ctrl) and during (ACh) the application of ACh. Bottom: Magnified display of the current trace before (Ctrl: left) and during (ACh: right) the application of ACh (highlighted in yellow). (C and E) Summary of ACh effects on the frequency (left), mean amplitude (middle), and averaged charge transfer (right) of PSCs in ON SACs (C: frequency, P = 2.09 × 10−8; mean amp., P = 0.000656; charge, P = 5.88 × 10−8; n = 29 cells from 23 mice) and OFF SACs (E: frequency, P = 8.27 × 10−8; mean amp., P = 0.00481; charge, P = 4.12 × 10−6; n = 27 cells from 21 mice). Data represent means + SEM. A paired t-test was used. **P < 0.01, ***P < 0.001.