Figure 2.

Example intracellular responses to contralateral intraspinal stimulation. Three motoneurons recorded in the same experiment are illustrated, identified as projecting to the muscle groups labeled at the top of each column. A, Antidromic activation from peripheral nerve. The motoneuron in the central panel shows both antidromic and subsequent orthodromic spikes. B, Mean intracellular response to contralateral intraspinal microstimulation (100, 180, and 200 μA stimulus currents, respectively). C, Single-sweep intracellular potentials that contributed to the averages in B. D, Averaged cord dorsum potential responses recorded simultaneously as B. Arrows indicate time of stimulation.