Spinal Nerve RootsSpinal NervesPeripheral Nervous System NeoplasmsNerve Compression SyndromesSpinal CordLumbosacral RegionRadiculopathyLumbar VertebraeNeuralgiaNerve FibersSpinal Cord InjuriesInjections, SpinalMagnetic Resonance ImagingSciatic NerveSciaticaPeripheral Nerve InjuriesLigationPeripheral NervesLumbosacral PlexusGanglia, SpinalHyperalgesiaPeripheral Nervous System DiseasesCauda EquinaIntervertebral Disc DisplacementNerve BlockSpinal CanalRats, Sprague-DawleySpinal Cord NeoplasmsSpinal StenosisCervical VertebraePainSacrumPain MeasurementMyelographyNerve Fibers, MyelinatedOptic NervePain ThresholdNerve RegenerationEpidural SpaceSpinal DiseasesSpinal Cord DiseasesCervical PlexusSpinal Cord CompressionLaminectomyNeurons, AfferentMotor NeuronsAxonsRhizotomyMononeuropathiesTooth RootPosterior Horn Cells