Experiments on the mechanism of Ménière attacks.

The pattern of response decline following semicircular canal stimulation corresponds to a mechanical process. This process is the elastic recoil of the hairs of the sensory cells. The response decline is the same, whether the endolymph-cupula system is patent or mechanically maintained in a displaced position. The role of the bending of the entire cupula as the principle factor is excluded for the response and its decline. Repeated endolymph displacements immediately after each decline of response always result in an equal response and its decline. This rules out the depletion of a chemical mediator as a cause for the response decline. Indentations of the sidewalks of the ampulla result in reactions suggesting that the ampulla is filled with a loose gel secreted by the planum semilunatum cells.