The role of the crossed and uncrossed retinal fibres in mediating the horizontal optokinetic nystagmus in the cat.

While the horizontal optokinetic nystagmus (OKN) was studied in cats in which the optic chiasma was completely split thus leaving only uncrossed retinofugal fibers intact it was found that both temporonasal and nasotemporal surround motion generated symmetrical OKN. Similar findings were obtained when one optic tract was sectioned and the eye ipsilateral (uncrossed fibers only) or contralateral (crossed fibers only) to the lesion was covered. It is concluded that in the cat the crossed and uncrossed retinofugal fibers are equipotent in mediating symmetrical OKN.