The pretrigeminal cat as an instrument for investigation of the ocular fixation reflex

Abstract

The fixation reflex is an important representative of orienting (targeting) reflexes. In the cat with the brainstem transected at the pretrigeminal level the fixation reflex is easy to investigate for the following reasons: (a) all sensory inputs to the isolated cerebrum of the pretrigeminal cat are eliminated, except for visual afferents, (b) the isolated cerebrum is continuously awake, (c) the vertical fixation reflex only is present. The behavioral and neural characteristics of the fixation reflex in the pretrigeminal cat are reviewed.