Conditioning Lesions Enhance Axonal Regeneration of Descending Brain Neurons in Spinal-Cord-Transected Larval Lamprey

摘要: In larval lamprey, with increasing recovery times after a transection of the rostral spinal cord, there is gradual locomotor behavior, and descending brain neurons regenerate their axons for progressively greater distances below site. present study, cord “conditioning lesions” (i.e., transections) were performed in at 30% body length (BL; normalized distance from head) or 50% BL. After various “lesion delay times” (D), more proximal “test lesion” transection) was 10% BL, then, (R), horseradish peroxidase applied to 20% BL determine extent axonal regeneration neurons. Conditioning lesions lesion 2 weeks, 4 weeks (D-R = 2–4 group) resulted significant enhancement total numbers as well certain cell groups compared control animals without conditioning lesions. Experiments hemiconditioning lesions, which reduce interanimal variability, confirmed that do significantly enhance indicate axotomy rather than diffusible factors released injury site primarily involved this enhancement. Results study suggest “prime” via responses subsequent regeneration, probably by reducing initial and/or rate outgrowth.