Figure 1.

Example of a reflex response recorded from the ventral roots (10 consecutive sweeps superimposed). Stimulation of an L5 dorsal root (500 μA, 500 μsec, at asterisk) induced a reflex response in the corresponding ventral root that consisted of a monosynaptic (1) and a longer-latency reflex response (2). Note that the longer-latency response consists here of two epochs that can be easily distinguished, at ∼15-30 and ∼40-60 msec after the onset of the MSR, respectively. The boxed regions identify those epochs chosen to calculate the amplitude of monosynaptic and longer-latency reflexes. The MSR component is expanded horizontally to highlight the 3 msec period and show its stability.