Figure 2.

Time course of behavioral recovery in lamprey after spinal cord transection. The lamprey spontaneously recovers swimming movements after complete spinal cord transection in a stereotypic manner over the course of 12 weeks. The numbers on the y-axis correspond to reproducible stages of recovery and are adapted from Oliphint et al. (2010). Briefly, a score of 0 indicates that the animal can move its head rostral to the transection site and is paralyzed below it. A score of 1 indicates that the animal can curl into a C- or S-shape. A score of 2 indicates the ability to accomplish abnormal, brief bouts of self-initiated swimming. A 3 indicates the ability to sustain more persistent, but still abnormal, bouts of swimming, including abnormal body contractions and difficulty righting. Finally, a score of 4 indicates that the animal can swim consistently, persistently, in a manner that appears as if uninjured. Data are derived from the mean ± sem of 5–6 animals (Bloom, O, unpubl. data).