Synaptic fluctuations in motoneurons are unaffected by transection. A, Membrane potential from a sample neuron during a scratch reflex (Iinj = 0). Spike times are indicated by cyan vertical lines. Selected off cycles are indicated by magenta bars. B, Synaptic fluctuations in on cycles are assessed as the trial variance of Vm, 18 ms before the triggered spikes (Berg et al., 2008), for intact (cyan) and transected (gray). C, Synaptic fluctuations in off cycles are assessed as SDs in 200 ms windows of Vm across time and cycles. D, E, Population distribution of synaptic fluctuations in intact (n = 10 cells) and transected (n = 8 cells) for the on cycle (cyan, D) and off cycle (magenta, E). Intact and transected populations are statistically indistinguishable in on cycles and in off cycles, using a Kolmogorov-Smirnov two-sample test (α = 5%).