Figure 7.

Example synaptic responses to contralateral peripheral nerve stimulation. A–C, Responses in three different motoneurons, projecting to an intrinsic hand muscle, a forearm flexor muscle, and a muscle proximal to the elbow, respectively. A1, B1, C1, Antidromic response after ipsilateral nerve stimulation (note the additional orthodromic action potential in A1). A2, B2, C2, Intracellular response to single stimulus to a contralateral nerve. A3, B3, C3, Simultaneously recorded cord dorsum potential. A4, B4, C4, Synaptic response after three stimuli to the contralateral nerve. A5, B5, C5, Simultaneously recorded cord dorsum response. A6, B6, C6, Same as A5, B5, C5, but with a longer time base. Vertical dotted lines throughout indicate the times of stimulation. A, Responses were to contralateral median nerve at the arm. B, C, Responses were to contralateral ulnar nerve at the arm. Stimulus intensities in all cases was 3 × MT.