ABSTRACT
The plugging of a semicircular canal creates a special condition: the endorgan sends out normal static signals with no dynamic modulations. The natural stimulus for the ampullary endorgans is rotatory acceleration which can be by velocity steps to different speeds, and/or by pendular rotation at different frequencies in different planes of rotation. Rotatory acceleration is sensed by the ampullary endorgans through cupular deflections. Thermal stimuli cannot be exclusive to one or two endorgans, but involve all endorgans of the labyrinth. Thermal stimulations are entirely different from rotations since unilateral stimulation is possible with calorization. Calorization, accordingly, may induce cupula deflections in different degrees in all three ampullae, but, at the same time, it may also directly stimulate the sensory cells and the nerve endings of the ampullary and the otolithic organs. Canal plugging experiments may provide a new approach in clarifying the mechanism of caloric responses.
