A theoretical approach to understanding of the vestibular perception organization in microgravity condition.

This paper should be viewed as a part of our attempts to arrive at a quantitative understanding of some contradictory experimental phenomena in the vestibular perception. The most popular remains the Steinhausen's model of perception, in which the endolymph circulation, caused by the angular acceleration, is "measured" by the displacement of cupulae diaphragm. Though displacements of the cupulae top were experimentally observed, the thorough mathematical analysis shows that the applicated stop-stimuli were too much over the range of adequate stimulation conditions, so the cupulae was teared off from its normal position. The more natural mechanism of perception was proposed by McLaren & Hillman. It was experimentally demonstrated that the cupulae diaphragm remained margin attached during the normal stimulation conditions only with its bottom moved according to the value of the applicated angular acceleration. A question only arises, how will be the hair cells excited by low level stimulation, when elastic deformations of the cupulae are small and there is no visible shift of the cupulae bottom? The response is to find in the third mechanism formulated by Schmaltz, which connected the excitation of hair cells with the process of endolymph diffusion through the cupulae towards the subcupulae space.