Nerve root injury severity differentially modulates spinal glial activation in a rat lumbar radiculopathy model: considerations for persistent pain. 2002

Beth A Winkelstein, and Joyce A DeLeo
Department of Anesthesiology, Dartmouth, Hitchcock Medical Center, Lebanon, NH 03756, USA. winkelst@seas.upenn.edu

Nerve root deformation magnitude affects behavioral sensitivity and spinal cytokine expression in a lumbar radiculopathy model. Despite evidence suggesting spinal glia play a role in persistent pain, no study has examined the relationship between injury severity in painful radiculopathy and spinal glial activation. This study quantified local in vivo biomechanics for nerve root injury, describing effects on temporal glial activation. Sham rats had only nerve root exposure; ligation rats received a tight L5 nerve root ligation with silk suture. Using image analysis, the magnitude of nerve root compressive strain was calculated at the time of injury. Mechanical allodynia was assessed from days 1 to 14 following injury and spinal microglial and astrocytic expression were evaluated using immunohistochemistry on days 1, 3, 7, and 14. More severe ligations produced greater microglial activation, indicating injury severity modulates spinal microglial activation. However, astrocytic activation levels did not demonstrate any relationship with the degree of initial injury severity. While allodynia decreased slightly over time following injury, the temporal changes in mechanical allodynia were not significant. Microglial activation levels were maintained temporally, and in some cases increased over time; whereas, changes in astrocytic activation levels were not temporally or injury-related. While initial nerve root injury severity likely modulates spinal OX-42 (CR3/CD11b) expression, OX-42 staining does not directly correlate with nerve root injury-induced mechanical allodynia.

UI MeSH Term Description Entries
D007150 Immunohistochemistry Histochemical localization of immunoreactive substances using labeled antibodies as reagents. Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008161 Lumbosacral Region Region of the back including the LUMBAR VERTEBRAE, SACRUM, and nearby structures. Lumbar Region,Lumbar Regions,Lumbosacral Regions,Region, Lumbar,Region, Lumbosacral,Regions, Lumbar,Regions, Lumbosacral
D008297 Male Males
D010146 Pain An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS. Suffering, Physical,Ache,Pain, Burning,Pain, Crushing,Pain, Migratory,Pain, Radiating,Pain, Splitting,Aches,Burning Pain,Burning Pains,Crushing Pain,Crushing Pains,Migratory Pain,Migratory Pains,Pains, Burning,Pains, Crushing,Pains, Migratory,Pains, Radiating,Pains, Splitting,Physical Suffering,Physical Sufferings,Radiating Pain,Radiating Pains,Splitting Pain,Splitting Pains,Sufferings, Physical
D011843 Radiculopathy Disease involving a spinal nerve root (see SPINAL NERVE ROOTS) which may result from compression related to INTERVERTEBRAL DISK DISPLACEMENT; SPINAL CORD INJURIES; SPINAL DISEASES; and other conditions. Clinical manifestations include radicular pain, weakness, and sensory loss referable to structures innervated by the involved nerve root. Nerve Root Avulsion,Nerve Root Compression,Nerve Root Disorder,Radiculitis,Nerve Root Inflammation,Radiculopathy, Cervical,Avulsion, Nerve Root,Avulsions, Nerve Root,Cervical Radiculopathies,Cervical Radiculopathy,Compression, Nerve Root,Compressions, Nerve Root,Inflammation, Nerve Root,Nerve Root Avulsions,Nerve Root Compressions,Nerve Root Disorders,Nerve Root Inflammations,Radiculitides,Radiculopathies,Radiculopathies, Cervical
D004195 Disease Models, Animal Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases. Animal Disease Model,Animal Disease Models,Disease Model, Animal
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001253 Astrocytes A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury. Astroglia,Astroglia Cells,Astroglial Cells,Astrocyte,Astroglia Cell,Astroglial Cell,Astroglias,Cell, Astroglia,Cell, Astroglial
D013126 Spinal Nerve Roots Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS. Dorsal Roots,Spinal Roots,Ventral Roots,Dorsal Root,Nerve Root, Spinal,Nerve Roots, Spinal,Root, Dorsal,Root, Spinal,Root, Spinal Nerve,Root, Ventral,Roots, Dorsal,Roots, Spinal,Roots, Spinal Nerve,Roots, Ventral,Spinal Nerve Root,Spinal Root,Ventral Root
D013997 Time Factors Elements of limited time intervals, contributing to particular results or situations. Time Series,Factor, Time,Time Factor

Related Publications

Beth A Winkelstein, and Joyce A DeLeo
May 2011, Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association,
Beth A Winkelstein, and Joyce A DeLeo
December 2016, Hiroshima journal of medical sciences,
Beth A Winkelstein, and Joyce A DeLeo
February 2014, European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society,
Beth A Winkelstein, and Joyce A DeLeo
October 2023, Cureus,
Copied contents to your clipboard!