[A neurophysiological study of accesary abducens motoneurons in the awake cat (author's transl)]

The activity of abducens and accessory abducens motoneurons (Mns) has been recorded during spontaneous and vestibularly or visually induced eye movements in awake cats. Motoneuronal activity was also recorded during corneal reflexes induced by the excitation of trigeminal terminals in the orbit. Recorded Mns were antidromically identified by electrical stimulation of the VI nerve. Accessory abducens Mns showed a burst of activity in response to trigeminal stimulation, but they did not show any response in relation to horizontal, vertical and/or oblique eye movements. On the contrary, abducens Mns firing activities were related to the position and velocity of the eye in the horizontal plane, without showing any change in their firing patterns in response to trigeminal stimulation in the orbit.