Vestibular lesions selectively abolish body rotation-induced, but not lithium-induced, conditioned taste aversions (oral rejection responses) in rats

Pairing a novel taste with provocative vestibular stimulation results in conditioned taste aversions in both rats and humans. Vestibular system involvement in gustatory conditioning was examined in shamlesioned or labyrinthectomized rats. Three conditioning trials consisted of 30 min access to a saccharin (0.1%) solution followed by 30 min of rotation (70 rpm) or sham rotation. In a taste reactivity test with saccharin, rotated sham-lesioned rats, but not labyrinthectomized rats, exhibited increased oral rejection reactions compared with control rats. When conditioned with lithium chloride, both labyrinthectomized and sham-lesioned rats displayed robust conditioned rejection reactions. The finding that normal vestibular function is necessary in obtaining rotation-induced conditioned taste aversions supports the face and construct validity of a rat model of motion sickness.