Spinal Nerve RootsSpinal NervesPeripheral Nervous System NeoplasmsNerve Compression SyndromesSpinal CordLumbosacral RegionRadiculopathyLumbar VertebraeNeuralgiaInjections, SpinalSpinal Cord InjuriesMagnetic Resonance ImagingSciatic NerveSciaticaPeripheral Nerve InjuriesLigationInjectionsPeripheral NervesLumbosacral PlexusHyperalgesiaGanglia, SpinalPeripheral Nervous System DiseasesNerve FibersIntervertebral Disc DisplacementCauda EquinaNerve BlockRats, Sprague-DawleySpinal CanalSpinal Cord NeoplasmsPainSpinal StenosisCervical VertebraePain MeasurementSacrumMyelographyPain ThresholdEpidural SpaceOptic NerveSpinal DiseasesNerve RegenerationSpinal Cord DiseasesCervical PlexusSpinal Cord CompressionLaminectomyRhizotomyMononeuropathiesNeurons, AfferentPosterior Horn CellsLow Back PainDisease Models, Animal