Study Design This blinded, histomorphometric analysis compared neuronal nuclei from lumbar dorsal root ganglia from three groups of rabbits: normal controls, immobilized controls, and an experimental group exposed to dally, whole body vibration. Objectives To identify ultrastructural changes in dorsal root ganglion neurons consistent with, and capable of producing, neuropeptide changes previously documented in vibration-exposed animals. Methods Normal adult rabbits were exposed to modulated whole body vibration at a frequency and amplitude previously shown to produce changes in dorsal root ganglion neuropeptides. Lumbar ganglia from control and vibrated rabbits were fixed, stained, and studied under transmission electron microscopy. One-thousand-two-hundred cells were sampled, and 190 appropriately sectioned cells were analyzed. Summary of Background Data Epidemiologic studies have suggested a strong correlation between vibration and back pain. Previous studies have shown that short-term exposure to whole body vibration alters the normal neuropeptide profile seen in dorsal root ganglion neurons. Results Nuclear clefting was increased 39% in vibrated nuclei relative to controls, and nuclear pores were increased 46% in areas of clefting compared with adjacent nonclefted segments and controls (<E T="I">P <. 001). Mitochondria, rough endoplasmic reticulum, and free ribosomes crowded the cleft spaces of vibrated cells, and the normal perinuclear clear space was lost. Mitochondrial and lysosomal volumes were significantly increased in vibrated cells. Conclusions These ultrastructural changes, generated by a physiologically valid vibration stimulus, provide an anatomic link between the clinical observations of increased back pain and the biochemical alterations involving pain-related neuropeptides.
- Dorsal root ganglion low back pain neuropeptides vibration
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Clinical Neurology