The saccadic system and the vestibulo-ocular reflex in the cat do not share the same integrator.

We have studied the effects of a neuroleptic, xylidino-dihydrothiazin (XDT), on the sinusoidally induced vestibulo-ocular reflex (VOR) and on the saccades. Very low doses of XDT caused a phase advance and a marked gain decrease at lower frequencies. This is the result one would expect if the integrator of the VOR pathway was off. Low doses of XDT did not affect the shape of the saccades (no post-saccadic slip was observed). This negative result is what one would expect if the integrator of the saccadic system was not disturbed by XDT. It was concluded that the vestibular and the saccadic systems do not share the same integrator.