Lesions in the cat prepositus complex: effects on the vestibulo-ocular reflex and saccades.

The effects of bilateral electrolytic lesions within and around the prepositus hypoglossi (p.h.) nucleus on horizontal saccades in the dark and on the horizontal sinusoidal vestibulo-ocular reflex (v.

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.