Vestibular compensation without brainstem commissures in the guinea pig.

The rapid recovery from the postural and ocular motor asymmetries produced by unilateral vestibular damage (vestibular compensation) has been presented as an example of plasticity in the central nervous system. A recent model (J. Neurophysiol., 51 (1984) 242-259) has identified the fibers joining the two vestibular nuclei in the brainstem (the vestibular commissures) as the site of the plastic changes. We report that in guinea pigs, compensation of postural symptoms still occurs after sectioning these commissural fibers. We suggest that a number of mechanisms may be responsible for vestibular compensation, including some which are independent of the vestibular commissures.