Acute vibration exposure alters current perception thresholds in the tails of rats.
Program No. 624.9, 2005 Abstract Viewer/Itenerary Planner, 2005, Washington DC: Society for Neuroscience, 2005 Jan; :1
Exposure to vibration through the use of powered hand-tools results in reductions in peripheral blood flow and tactile sensitivity. The goal of this study was to determine how exposure to a single bout of vibration affects sensory nerve fiber function by measuring current perception thresholds (CPTs). Male rats were restrained in Broome style restrainers. Tail temperatures were measured, and CPTs of AB, A and C fibers were assessed by applying stimuli of different frequencies transcutaneously along the tail, using a Neurometer. The rats were then placed in exposure chambers and their tails were strapped to platforms attached to shakers or isolation blocks. The tails of half of the rats were exposed to 4 h of continuous vibration (125 Hz, 49 m/s rms). The remaining rats were restrained, but were not exposed to vibration. Tail temperatures and CPTs were measured immediately after, and 18 h after the end of the exposure. Exposure to vibration and restraint conditions induced a transient reduction in tail temperature, suggesting that these exposures resulted in an acute vasoconstriction. Pre and post exposure CPTs of the A and C fibers were not different in either group of rats. However, immediately following exposure, the CPTs of the AB fibers were reduced in restrained rats, but increased in vibration exposed rats, indicating that restraint increased, but vibration decreased the sensitivity of the AB fibers to stimulation. All CPTs were back to pre-exposure levels 18 h later. AB fibers are large myelinated fibers that carry information from mechanoreceptors to the CNS. A vibration-induced reduction in AB fiber sensitivity may play a role in mediating decreases in grip strength and manual dexterity that are often apparent in workers that use vibrating hand tools. These findings suggest that CPTs could be used to assess mechanisms underlying vibration-induced neuropathies in the fingers and hands of workers with hand-arm vibration syndrome.
Acute-exposure; Vibration-exposure; Laboratory-animals; Animals; Animal-studies; Hand-tools; Exposure-chambers; Exposure-levels; Exposure-assessment; Vibration
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Program No. 624.9, 2005 Abstract Viewer/Itenerary Planner