Beneficial Effects of Whole Body Vibration on Brain Functions in Mice and Humans

Abstract

The biological consequences of mechanical whole body vibration (WBV) on the brain are not well documented. The aim of the current study was to further investigate the effects of a 5-week WBV intervention on brain functions. Mice (C57Bl/6J males, age 15 weeks) were exposed to 30 Hz WBV sessions (10 minutes per day, 5 days per week, for a period of 5 weeks; n = 10). Controls received the same intervention without the actual vibration (n = 10). Humans (both genders, age ranging from 44-99 years) were also exposed to daily sessions of 30 Hz WBV (4 minutes per day, 4 days per week, for a period of 5 weeks; n = 18). Controls received the same protocol using a 1 Hz protocol (n = 16). Positron emission tomography imaging was performed in the mice, and revealed that glucose uptake was not changed as a consequence of the 5-week WBV intervention. Whole body vibration did, however, improve motor performance and reduced arousal-induced home cage activity. Cognitive tests in humans revealed a selective improvement in the Stroop Color-Word test. Taken together, it is concluded that WBV is a safe intervention to improve brain functioning, although the subtle effects suggest that the protocol is as yet suboptimal.

Keywords: behavioral arousal; brain glucose metabolism; executive functions; motor performance.

Figure 1.

A, Set-up of the mouse platform: a box (2), (length: 44.5 cm, width: 28 cm; height: 16 cm) is connected to a vibrator (1). Mice are placed in separate compartments (3) to avoid social interactions (eg, fights between males); 4 = amplifier; 5 = oscillator. B, Set-up of the human platform, with a chair mounted on a vibration platform suitable for wheel chairs.

Figure 2.

Balance beam crossing time of the WBV and pWBV mice (n = 10 each), before (black bars) and after (white bars) the 5 week WBV protocol. Only the WBV animals increased their performance statistically significant (*2-way-RM-ANOVA: post-hoc Holm-Sidak for WBV: t = 2.989; P = .008). pWBV denotes pseudo whole body vibration; RM-ANOVA, repeated measures analysis of variance; WBV, whole body vibration.

Figure 3.

(A) Distance moved per 60 seconds bin, averaged per animal for days 1, 18, and 37. The corresponding effect sizes (Cohen d) are shown in (B). (Error bars are SEM; *two-way-RM-ANOVA: post-hoc Holm-Sidak for WBV vs pWBV: t = 2.553; P = .018). (C) Distance moved when returned to the home cage in the first minute after the first WBV session (day 1), after 2.5 weeks (day 17), and at the end of the WBV intervention (day 37) (Error bars are SEM; *2-way-RM-ANOVA: post-hoc Holm-Sidak for WBV vs pWBV: t = 2.553; P = .018). pWBV denotes pseudo whole body vibration; RM-ANOVA, repeated measures analysis of variance; SEM, standard error of the mean; WBV, whole body vibration.

Figure 4.

Overview of the average brain ¹⁸F-FDG uptake in %ID/g (bar-chart) pre- and post-treatment for the WBV and pWBV mice. The top right panel shows an overlay of the ¹⁸F-FDG PET data with the C57Bl/6 J mouse MRI brain atlas in the horizontal, coronal, and sagittal plane. The light colored region indicates the brain regions included in the ROI. The darker colored regions (bulbus, caudal part of the brain-stem) are excluded from the ROI. The bottom 4 panels show the average uptake for the WBV and pWBV mice (n = 10 each) before and after the WBV intervention. ¹⁸F-FDG denotes ¹⁸F-fluorodeoxyglucose; %ID/g, %Injected Dose per gram; MRI, magnetic resonance imaging; PET, positron emission tomography; pWBV, pseudo whole body vibration; ROI, region of interest; WBV, whole body vibration.

Figure 5.

Stroop Color-Word test scores for the experimental (WBV) and the control (pWBV) group pre (black bars) and post (white bars) intervention. Error bars are SEM; *P < .05. pWBV denotes pseudo whole body vibration; SEM, standard error of the mean; WBV, whole body vibration.