Effects of vibration on cutaneous silent period

• Published in: Experimental brain research Vol. 237; no. 4; pp. 911 - 918
• Main Authors: Aydın, Şenay, Kofler, Markus, Bakuy, Yeliz, Gündüz, Ayşegül, Kızıltan, Meral E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2019; Springer; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Brain research; Electromyography; Genetic aspects; Influence; Interneurons; Latency; Mechanoreceptors; Muscle contraction; Neural receptors; Neurology; Neurosciences; Physiological aspects; Research Article; Thoracic surgery; Turkey; Cutaneous silent period; Alpha motoneuron; Vibration; A delta fiber; Group Ia afferent fibers; Exteroceptive suppression
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-018-05463-1

Suppression of an ongoing muscle contraction following noxious digital stimulation is called cutaneous silent period (CSP) which is under the influence of several physiological factors. In this study, we aimed to evaluate the influence of group Ia afferents on the cutaneous silent period (CSP) by applying 2-min vibration. CSP was obtained from abductor pollicis brevis muscle after stimulating index finger. The recordings were repeated three times—before, during and after vibration—which was applied over the tendon of flexor carpi radialis muscle. Onset latency, duration and magnitude of total CSP, inhibitory phases I1 and I2, and of the long-loop reflex were measured and compared. Suppression indices of CSP, I1 and I2 increased significantly during and after vibration, indicating significantly less exteroceptive EMG suppression outlasting the time of vibration. Vibration also caused mild shortening of I2 end latency (
p
 = 0.048) and I2 duration (
p
 = 0.019). Our findings indicate that vibration exerts a powerful influence on CSPs and causes reduction in the magnitude of exteroceptive EMG suppression during and after vibration. Although vibration is known to activate Ia afferents, we cannot exclude contribution of other afferents, e.g. mechanoreceptors, as well as pre- or postsynaptic inhibitory effects on ensuing interneurons, or enhanced vibration-related excitatory influence.