Figure 3.

A caudal transection has marginal effects on motor activity. A, Lumbar enlargement of the turtle spinal cord. Spinal segments and nerves are labeled. The transection is performed at the caudal end of segment D10 (dashed line), to allow access to the motoneuron in D10. B, C, Four simultaneous ENGs during scratch reflex measured before (cyan) and after (magenta) transection. One cycle from each recording is highlighted. D, Normalized single-trial ENG power of scratch behavior (frequency band, 0.3–0.9 Hz) in chronological order. The recordings in B and C are indicated by ★ and †, respectively. E, Average power across trials in D. Significant difference is indicated (★★★). F, Coherence between three nerve pairs (I, hip flexor vs extensor; II, dD8 vs hip flexor; III, hip flexor vs knee extensor) at the dominant frequency. Dots indicate single trials, and arrows indicate trial average.