Patterns of gene Expression during the Spinal cord Injury/Regeneration

Spinal cord injury (SCI) induces a sequence of endogenous autodestructive changes known as secondary injury, as well as reactive biochemical changes that are neuroprotective and/or promote recovery. All these responses to SCI are, in part reflected in changes in gene expression. In order to assess changes in gene expression involved in the regeneration process,microarrays were performed as a function of time after SCI for the various treatments. Three groups rats(i.e.NT-3-chitosan tube group, tube alone group and lesion control group) used to interrogate Affymetrix (SantaClara,CA) GeneChips were sacrificed by intraperitoneally over dose injecting 6% chloral hydrate at 1, 3, 10, 20, 30, and 90 d after the operation. The spinal cords were surgically re-exposed and spinal tissue including dura and meninges was dissected into three blocks, i.e. 5 mm long segments in the lesioned area (M), rostral to the lesioned area (R), and caudal to the lesioned areas (C) were sampled under RNAase-free conditions. The samples were quick frozen and kept in liquid nitrogen.