The relationship between the vestibular system and the circadian timing system: A review

This review attempts to analyze the relationship between the vestibular system and the circadian timing system. The activity of the biological clock allows an organism to optimally perform its tasks throughout the nychtemeron. To achieve this, the biological clock is subjected to exogenous factors that entrain it to a 24h period. While the most powerful synchronizer is the light-dark cycle produced by the Earth's rotation, research has led to the hypothesis of the vestibular system as a possible non-photic time cue used to entrain circadian rhythms. Demonstrated neuroanatomical pathways between vestibular nuclei and suprachiasmatic nuclei could transmit this message. Moreover, functional evidence in both humans and animals has shown that vestibular disruption or stimulation may lead to changes in circadian rhythms characteristics. Vestibular stimulations could be considered to act synergistically with other synchronizers, such as light, to ensure the entrainment of biological rhythms over the 24-h reference period. •In addition to light, the vestibular system could act as possible non-photic synchronizer for circadian rhythms.•Neuroanatomical pathways have been identified between the vestibular system and biological clock.•Bilateral vestibular loss in both humans and animals leads to modifications in diurnal rhythms and sleep characteristics.•Hypergravity causes a disappearance of diurnal rhythms of temperature and locomotor activity for several days to weeks.•Involvement of the vestibular system could then provide a signal relating to awakening transmitted to the biological clock.