Figure 3.

Synaptic recruitment of mAChRs mediates sustained suppression of recurrent activity. A, Representative recording showing normalized EPSCs during unpaired (black) and paired (blue) trials, for a range of temporal delays between optical and electrical stimulation (15–8000 ms). B, Summary data quantifying light-evoked suppression of recurrent activity (normalized to responses in unpaired trials) as a function of temporal delay between and electrical stimulation (n = 5 cells). Summary data were fit by a third order polynomial (χ² = 0.013). C, Representative recording showing that for 5 s delays between optical and electrical stimulation, suppression of recurrent activity (blue) was entirely reversed by bath application of atropine. D, Summary data showing elimination of light-evoked suppression of recurrent activation following bath application of either atropine or 10 μm AF-DX 116 (circles: atropine, n = 7 cells; triangles: AF-DX 116, n = 4 cells), for experiments as shown in C. **p < 0.01. Shaded areas and error bars denote SEM.