Whole Body Vibration Improves Brain and Musculoskeletal Health by Modulating the Expression of Tissue-Specific Markers: FNDC5 as a Key Regulator of Vibration Adaptations

Abstract

Whole body vibration (WBV) is well known to exert beneficial effects on multiple tissues, improving synaptic transmission, muscle mass, bone quality, and reducing anxiety and depressive behavior. However, the underlying molecular mechanisms are not yet fully understood, and organs and tissues may respond differently to the vibratory stimulus depending on multiple factors. Therefore, we investigated the WBV effects on the brain and musculoskeletal tissue of 4-month-old young mice, evaluating synaptic plasticity by electrophysiological recordings and tissue organization by histology and histomorphometric analysis. Specifically, WBV protocols were characterized by the same vibration frequency (45 Hz), but different in vibration exposure time (five series of 3 min for the B protocol and three series of 2 min and 30 s for the C protocol) and recovery time between two vibration sessions (1 min for the B protocol and 2 min and 30 s for the C protocol). In addition, immunohistochemistry was conducted to evaluate the expression of fibronectin type III domain-containing protein 5 (FNDC5), as well as that of tissue-specific markers, such as brain-derived neurotrophic factor (BDNF) in brain, myostatin in muscle and collagen I (COL-1) in bone. Our results suggest that the WBV effects depend closely on the type of protocol used and support the hypothesis that different organs or tissues have different susceptibility to vibration. Further studies will be needed to deepen our knowledge of physiological adaptations to vibration and develop customized WBV protocols to improve and preserve cognitive and motor functions.

Whole Body Vibration: A Valid Alternative Strategy to Exercise?

“…In contrast, the other vibration training protocols, which differed in vibration frequency, vibration exposure time and recovery time, were found to be too stressful, inducing the appearance of an epileptic tendency and possibly damaging the hippocampus and other brain structures related to memory functions [ 31 ]. These results were later confirmed by the same authors through histological and morphometric analyses, showing that reduced synaptic function was associated with the presence of structural alterations, including a reduction in the number of Purkinje cells in the cerebellum, as well as reduced or even absent pyramidal neurons in the hippocampus, indicating WBV-induced sensory stimulation as an essential part of the mechanism underlying the improved cognitive performance in mice [ 32 ].…”

“…Similarly, Shan and colleagues showed that knockout of the myostatin gene produces an increase in the muscle mass and browning of adipose tissue, effects known to be attributed to irisin [ 86 ]. In agreement with this, Cariati et al recently studied the potential effects of WBV on the expression of FNDC5 and tissue-specific markers such as BDNF in brain, myostatin in muscle, and collagen I (COL-1) in the bone of 4-month-old young mice [ 32 ]. Interestingly, increased expression of FNDC5, improved tissue structural organization and increased BDNF expression were detected after exposure to a WBV protocol with shorter vibration exposure times and longer recovery times.…”

“…These results were recently confirmed by the same authors in a study on 4-month-old young mice, showing that animals exposed to the less-stressful WBV protocol had the largest mean muscle fiber diameter and the least amount of inter-fiber connective tissue compared to the other experimental groups. Interestingly, histological and morphometric analysis also showed an improvement in the qualitative characteristics of bone tissue, such as higher bone volume and trabecular thickness and less trabecular separation compared to sedentary animals [ 32 ]. Indeed, increased bone mass and improved structural parameters in healthy young rodents are well documented.…”

“…Interestingly, increased expression of FNDC5, improved tissue structural organization and increased BDNF expression were detected after exposure to a WBV protocol with shorter vibration exposure times and longer recovery times. Furthermore, increased FNDC5 expression was found in the muscles and bones of trained mice, as well as reduced myostatin expression and increased COL-1, confirming WBV as a valid strategy to preserve musculoskeletal health [ 32 ].…”

Effects of Sitting Callisthenic Balance and Resistance Exercise Programs on Cognitive Function in Older Participants

“…As physical exercise leads to an induction of FNDC5 in the hippocampus, the PGC1a/FNDC5/BDNF pathway has been proposed as playing a role in the neuroplastic effects of physical exercise [ 10 , 11 ]. Animal-based studies have also shown that three months of a whole-body vibration program might lead to the modulation of FNDC5 expression and BDNF in the brain [ 12 ]. Irisin is a cleaved version of FNDC5 and has been suggested as a potential mediator of the beneficial effects of exercise on human metabolism [ 13 ].…”