Abstract
As part of a series of studies on the mechanism of interreaction between vestibular system and autonomic nervous system, the authors reported here the behavior of peripheral circulating system as induced by rotational vestibular stimulation. Observation was made about 49 persons, 35 of whom were confirmed to be physically defective by the routine vestibular functional test. All the subjects were stimulated in their vestibular systems with “0-144°/sec for two minutes-then a sudden stop” on the electric rotating chair, and the Bi-Auricular Plethysmographs (B. A. P. G.) were recorded during and after the stimulation. Concerning the normal subjects, the shift of autonomic nervous tonus to the sympathetic side was indicated with more reduced amplitude of B. A. P. G. as compared with the prerotatory amplitude in CW as well as ACW rotatory stimulation, while the shift to the parasympathetic side was indicated with more increased amplitude of B. A. P. G. in postrotatory stimulation. Further more there was a certain unbalance in the above mentioned shifts (vegetative asymmetry) found with remarkable regularity; the CW stimulation brought about even more emphasized response in the right A. P. G. than in the left, and the ACW gave greater shifts in the left A. P. G. than in the right. In our preceding reports the derection of the vegetative asymmetry was promised to be the one to the side of larger amplitude, so that the above mentioned results for the vegetative asymmetry are summarized as follows: the nystagmus and the vegetative asymmetry as induced by rotatory or postrotatory stimulation have contralateral directional relation to each other. We have concluded from the preceding results that the rotatory nystagmus seems to be the active while the postrotatory nystagmus as the passive vestibular function, and that the vegetative asymmetry which is liable to go to the contralateral direction against the rotational nystagmus is understood as having a biological meaning to reduce unfavorable functional change as much as possible.
