Figure 4.

Comparison of voltage trajectories recorded intracellularly from hip-flexor (VP-HP) motor neuron (top trace in A) and hip-extensor (HR-KF) motor neuron (top trace in B) during normal rostral scratch and during hip-extensor deletion rostral scratch. In (A) and (B) ENG recordings from monoarticular knee-extensor nerve (FT-KE; second trace), hip-flexor nerve (VP-HP; third trace) and hip-extensor nerve (HR-KF; bottom trace). (A) Hip-extensor motor neuron activity is deleted in first two cycles (marked with filled triangles). Hip-flexor motor neuron intracellular recording shows corresponding deletion of hyperpolarization normally associated with hip-extensor activity (compare with last three cycles showing hip-extensor nerve activity). (B) Hip-extensor nerve activity is deleted in the first and third cycles (marked with filled triangles) and is associated with a complete absence of depolarization in the hip-extensor motor neuron intracellular recording (compare with cycles with hip-extensor nerve activity). Calibrations: 1 s, 20 mV. From⁷ and used with permission of and copyright 1988 by The Physiological Society and Wiley-Blackwell.