Bilateral labyrinthectomy causes long-term deficit in object recognition in rat.

It has been reported that patients with vestibular disorders experience a wide range of cognitive disorders, including memory loss. However, to our knowledge, no study has investigated the contribution of vestibular information to episodic memory in experimental animals using vestibular deafferentation. In the present study, the effects of a complete unilateral or bilateral surgical lesion of the vestibular labyrinths in a spontaneous object recognition task were evaluated in Wistar rats 3 and 6 months following the surgery. We found that rats with bilateral vestibular deafferentation, but not those with unilateral vestibular deafferentation were impaired on the task at both time points. These results suggest for the first time that vestibular information may contribute to non-spatial memory to some extent.