Regulation of Axonal Regeneration Following Spinal Cord Injury in the Lamrpey (original) (raw)

2017, Journal of neurophysiology

Following rostral spinal cord injury (SCI) in larval lampreys, injured descending brain neurons, particularly reticulospinal (RS) neurons, regenerate their axons, and locomotor behavior recovers in a few weeks. However, axonal regeneration of descending brain neurons is mostly limited to relatively short distances, but the mechanisms for incomplete axonal regeneration are unclear. First, lampreys with rostral SCI exhibited greater axonal regeneration of descending brain neurons, including RS neurons, as well as more rapid recovery of locomotor muscle activity right below the lesion site compared to animals with caudal SCI. In addition, following rostral SCI, most injured RS neurons displayed the "injury phenotype", while following caudal SCI, most injured neurons displayed normal electrical properties. Second, following rostral SCI, at cold temperatures (~4-5oC), axonal transport was suppressed, axonal regeneration and behavioral recovery were blocked, and injured RS neuro...