Spinal cord injury: spinal tracts reconnection promotes the recovery of locomotor system functions

HR QUINTÁ

Congreso; Sociedad Argentina de Investigación Clinica; 2019

SAIC

In spinal cord injury (SCI) trauma, the shaftof long motor and sensory spinal tracts is interrupted. Therefore the goal inthis pathology is focused not only in promotes re-growth of spinal tracts butalso in an effective re-connection whit the lower targets to achieve a recoveryof locomotor functions. According to this background, I focus my researchin the design of protein treatments to this traumatic pathology. Netrin-1, anaxonal chemoattractant protein, is involved in axonal growth during theembryonic development. This protein drives the corticospinal tract growth andits navigation across the pyramidal decussation to the lowest part of spinalcord by a haptotaxis phenomenon.As I described previously, Netrin-1 treatmentpromotes a significant recovery of locomotor activity in rats with a completeSCI at thoracic level 10, assessed by using BBB score. Moreover, this result correlatedwith an improvement in the control of voluntary locomotion assessed with the ladderrung test. Rats treated with Netrin-1 showed a decreased number of missed stepsand slipped steps in the ladder compared to controls. In line with this, a stereotaxic surgery totrace the corticospinal tract was carried out in the treated rats. Using?clearing technique? plus ultrathin sectioned; it was observed a significant regenerationof corticospinal tract at the injury site in Netrin-1 treated animals.Moreover, a significant maintaining in the number of synaptic contact wasobserved downstream of lesion site only in rats that received Netrin-1treatment. Besides, the sensitive tracts were preserved of dying back only inrats treated with Netrin-1.In conclusion, Netrin-1 administration afterSCI promotes corticospinal tract regeneration avoids the dying back in thesensitive axonal shaft structure and stimulated the synaptic contactre-arrangement. All of these processes could partially explain the mechanism bywhich Netrin-1 treatment recover locomotor abilities after injury.