Behavioral properties of the trigeminal somatosensory system in rats performing whisker-dependent tactile discriminations

Abstract

To address several fundamental questions regarding how mul-tiwhisker tactile stimuli are integrated and processed by the trigeminal somatosensory system, a novel behavioral task was developed that required rats to discriminate the width of either a wide or narrow aperture using only their large mystacial vibrissae. Rats quickly acquired this task and could accurately discriminate between apertures of very similar width. Accurate discriminations required a large number of intact facial whis-kers. Systematic removal of individual whiskers caused a de-crease in performance that was directly proportional to the number of whiskers removed, indicating that tactile information from multiple whiskers is integrated as rats gauge aperture width. In different groups of rats, different sets of whiskers were removed in patterns that preferentially left whisker rows or whisker arcs intact. These different whisker removals cause