Fig. 9.

Extent of the areas from which disynaptic PSPs were evoked in contralateral motoneurons. A, B, Intracellular records from a GS motoneuron (moton.) showing effects of stimuli (70 μA) applied along the electrode track indicated in Figure 10A, dotted line, and descending (Desc.) volleys evoked by the same stimuli. C, D, Similar series of records from a Sart motoneuron and the descending volleys induced by stimuli (80 μA) applied along the electrode track indicated in Figure10B, dotted line. Double dotted lines in B and D coincide with the first and second components of the descending volleys.