Figure 1

Robust functional recovery after complete spinal cord transection in lampreys. (a) Diagram of lamprey brain and spinal cord showing location of transection site and tissues collected for molecular profiling (red boxes). Somata of RS neurons (arrows) reside in the midbrain and hindbrain, and their axons (black lines) extend the length of the spinal cord. (b) Images of uninjured lampreys and at 1wpi and 11wpi. Asterisks indicate lesion site. (c) Quantitative scale of functional recovery (i.e. swimming): Movement scores are as described fully in¹⁸: 0-paralysis); 1-head wiggle only; 2-brief, abnormal swimming; 3-persistent swimming with abnormal body shape; 4-apparently normal swimming. Data points represent mean ± SEM (n = 27–66 animals per data point). (d) Histological sections of lamprey spinal cord from uninjured, 3wpi, and 12wpi demonstrating cytological changes during the recovery from SCI. CC = central canal, RS axons = reticulospinal axons.