Lumbosacral RegionSacrumSpinal CordSpinal Cord InjuriesLumbosacral PlexusSpinal Cord DiseasesSpinal Nerve RootsSpinal Cord CompressionSpinal Cord NeoplasmsLumbar VertebraeInjections, SpinalSpinal Cord IschemiaMotor NeuronsCauda EquinaSpinal NervesSpinal CanalSpinal DiseasesBrain ChemistrySpinal NeoplasmsParaplegiaRadiculopathySpinal FusionRats, Sprague-DawleyBrain Injuries