An integrated biomechanical–vestibular neural model for predicting locus coeruleus activity during whole-body vibration

Abstract Whole-body vibration (WBV) influences not only the mechanical responses of the human body but also arousal-related neural activity. However, the integrated mechano-neural pathway linking WBV to locus coeruleus (LC) activity remains unclear. This study developed a numerical simulation framework that connects whole-body and head dynamics, vestibular encoding, and LC activity. Head motion under WBV was reproduced using a finite element human body model. The head motion-induced angular velocity and linear acceleration at the vestibular organs were used as inputs to the semicircular canal and otolith organ models, respectively, and the resulting vestibular signals were then provided to an LC Hodgkin–Huxley-type model. The validity of each model component was evaluated by comparison with experimental data. Simulations of seated vertical WBV predicted an increase in LC firing around 5 Hz. Because the present neural model relies on parameters derived from animal studies, the predicted frequency-specific responses should be interpreted with caution. Within this limitation, this study contributes to the development of a mechanistic framework for examining how WBV-induced head motion and vestibular encoding may modulate LC activity and potentially relate to physiological responses around this frequency range.