Acute vibration reduces A beta nerve fiber sensitivity and alters gene expression in the ventral tail nerves of rats.
Krajnak-K; Waugh-S; Wirth-O; Kashon-ML
Muscle Nerve 2007 Aug; 36(2):197-205
Long-term occupational exposure to hand-arm vibration can result in a permanent reduction in tactile sensitivity in exposed fingers and hands. Little is known about how vibration causes this reduction in sensitivity, and currently no testing procedures have been developed to monitor changes in sensory perception during ongoing exposures. We used a rat-tail model of hand-arm vibration syndrome (HAVS) to determine whether changes in sensory nerve function could be detected after acute exposure to vibration. Nerve function was assessed using the current perception threshold (CPT) method. We also determined whether changes in nerve function were associated with changes in gene transcription. Our results demonstrate that the CPT method can be used to assess sensory nerve function repeatedly in rats and can detect transient decreases in the sensitivity of A beta nerve fibers caused by acute exposure to vibration. This decrease in A beta fiber sensitivity was associated with a reduction in expression of nitric oxide synthase-1, and a modest increase in calcitonin gene-reiated peptide transcript levels in tail nerves 24 h after vibration exposure. These transient changes in sensory perception and transcript levels induced by acute vibration exposure may be indicators of more prolonged changes in peripheral nerve physiology.
Tissue-disorders; Musculoskeletal-system-disorders; Muscle-tissue; Biomechanical-modeling; Vibration-effects; Vibration-exposure; Sensory-perceptual-processes; Sensory-motor-system; Sensory-disorders; Threshold-limit-values; Nerve-function; Nerve-damage; Hand-injuries; Animal-studies; Arm-injuries; Genes
Kristine Krajnak, Engineering and Control Technology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505
Muscle & Nerve