Electronic Thesis and Dissertation Repository

Impact of Extremely Low-Frequency Magnetic and Electric Stimuli on Vestibular-Driven Outcomes

Nicolas Bouisset, The University of Western Ontario

Abstract

The vestibular system is extremely sensitive to electric fields (E-fields). Indeed, vestibular hair cells are graded potential cells and this property makes them very susceptible to small membrane potential modulations. Studies show that extremely low-frequency magnetic fields (ELF-MF) induced E-fields impact postural control in which the vestibular system plays an important role. However, the knowledge of whether this is indeed a vestibular specific effect is still pending.

Considering its crucial role and the specific neurophysiological characteristics of its hair cells, the vestibular system emerges as an ELF-MF likely target

The three studies presented in this thesis aimed to further address whether ELF-MF modulate vestibular-driven outcomes.

Studies 1 and 2 aimed to investigate postural responses while more specifically targeting the vestibular system. However, we did not find any modulation in either study. Nonetheless, based on both studies, study 3 aimed to determine whether the orientation and frequency of our stimulations were more likely to target the otoliths. Therefore, the third study looked at the subjective visual vertical. Here, we found a potential ELF-MF utricular modulation.

This thesis is the first steppingstone in a new field of research. Further investigations regarding the interaction between the ELF-MF and the vestibular system will have to look at more reflexives vestibular outcomes. Nonetheless, this thesis provides valuable information that will need to be taken into consideration when writing future international guidelines and standards related to ELF-MF.