Abstract
We opened one side of the middle ear of normal rabbits and gave caloric irritation to each semicircular canal ampullae, and isolating six eye-muscles on the same side or on the opposite side we connect kymographion and show curve from which we examine rhythmical movement.
In case of irritating horizontal semicircular canal ampulla, we observed rhythmical movement of horizontal eye-muscles, and besides it, the movement of vertical eye-muscles was also attended, But on the contrary, in case of irritating anterior semicircular canal ampulla, we observed the rhythmical movement of both oblique muscles, and at the sametime, we observed the movement of both horizontal and vertical muscles. But after eliminating each membraneous semicircular canal ampullae, of one side separately the remaining part of that side which is not eliminated, is semicircular ampulla to which we added locally caloric irritation (Yoshida's method) but we did not observe any change on spontaneous nystagmus. After eliminated each membraneous semicircular canal ampullae, of one side separately we applied caloric irritation on labyrinth of operated side and observed a change on spontaneous nystagmus: In time of cold irritation, amplitude of spontaneous nystagmus and its number decreases every time, but in warm water irritation, amplitude and the number increases every time. After iliminated each membraneous semicircular canal ampulla of one side separately, it is necessary to maintain healthy condition of horizontal semicircular canal ampulla of the same side for changing direction of the spontaneous nystagmus from caloric irritation of eliminated side in normal head-position of experimental animals.
After iliminated each membraneous semicircular canal ampulla of one side, when it passed 4-5 hours, it does not exert any influence over to spontaneous nystagmus, which is already existed, though we give strong caloric irritation to labyrinth of the same side. But caloric irritation which was given to external auditory meatus of the healthy side presents the influence according to the rules of direction of caloric nystagmus.
