Abstract
Recent study from our laboratory demonstrated that the vestibulo-sympathetic reflex plays an important role in controlling arterial pressure during gravitational change in conscious rats. Gravity acts on the circulatory system to reduce arterial pressure by reducing venous return, and vestibular system senses the gravitational change and increases sympathetic nerve activity to prevent hypotension. This type of circulatory stress occurs in human daily life upon postural change from spine to upright. However, the role of vestibular system in controlling arterial pressure in human is not clear. Thus the goal of the present study was to examine this. Postural change and gravitational change was produced by tilt-bed and parabolic-flight, respectively. To disturb the normal vestibular sensation, random galvanic vestibular stimulation was applied, and arterial pressure response to postural or gravitational change was compared with or without galvanic vestibular stimulation. [Jpn J Physiol 55 Suppl:S104 (2005)]
