Overt crawling behavior after a surgery combining denervation of the lead ganglion (M3) with a complete transection of the M2/M3 interganglionic connectives. A, B, Movement rasters depicting elongation (E, black boxes) and contraction (C, gray boxes) movements over time for an individual receiving an M3-denervation only surgical procedure (A) and a leech undergoing M3-denervation combined with M2/M3 connective transection (B). Movements are shown for time points before the surgery (Pre), and 4, 8, and 25 days after surgery. C, Graph showing the percentage of leeches exhibiting crawling behavior for M3-denervation only (n = 8), M2/M3 transection only (n = 10), and M3 denervation combined with M2/M3 transection (n = 11). Additional quantitative analyses are presented in the body of the Results section.