Ultrastructural changes in the dorsal root ganglion associated with whole body vibration

Morphological changes were identified in dorsal root ganglion (DRG) neurons of rabbits exposed to whole body vibration. Lightand electron-microscopic analysis were carried out in six vibrated and four control animals. Analysis by light microscopy revealed DRG cells ranging from <20 µ to >80 µ in diameter, with much less variation in nuclear diameter. Vibration had no effect on either cell or nuclear dimensions. There was no evidence of acute cellular injury in the vibrated specimens either on light or EM evaluation. However, mitochondria were increased 42% and lysosomes 33% in the vibrated specimens compared to controls. The incidence of nuclear membrane clefts was 2.70 per nucleus in control specimens and 3.74 per nucleus in vibrated specimens, an increase of 39%. These clefts were associated with numerous metabolic organelles, suggesting a relationship to cellular metabolism and, possibly, protein synthesis.