Spinal lumbar rhizotomy and the study of growth inhibitory molecules in regeneration

FITT, M.R.; RÁSMUSSEN, J.; LAURITO, S.R.; SAVASTANO, L.E.; PATTERSON, S.I.

Ciudad de San Juan

Congreso; II Reunión Conjunta de Sociedades de Biología de la República Argentina; 2011

Sociedad de Biología de Cuyo

Sensory neurons of the dorsal root ganglia are a popular model for investigating the consequences of injury due to an unusual characteristic – they send one pseudounipolar axon into both the peripheral and central nervous systems. While the former is capable of regenerating after injury (e.g. in the popular sciatic nerve crush model), regeneration of the same axon in the central root fails when it encounters the astrocytes of the spinal dorsal root entry zone. While the peripheral injury is a simple procedure, the central injury is far more invasive and difficult to perform. Here, we describe the anatomical guides and functional prerequisites for successful application of this model in Sprague-Dawley rats. Of particular importance is knowledge of the functional anatomy within the vertebral column, in order to ensure an accurate and limited lesion to the relevant spinal root. We describe the performance of lumbar spinal laminectomy on xylazine/ketamine anesthetized adult rats, the identification of the spinal roots corresponding to the peripheral sciatic nerve, and their axonotmesis. Issues of animal wellbeing are considered. This procedure allows the evaluation of factors contributing to failed regeneration at the peripheral/central boundary, the testing of potential interventions to overcome this barrier, and the morphological and functional assessment of correct recovery at the spinal level.