Modeling the role of the interstitial nucleus of Cajal in otolithic control of static eye position

Previous models of ocular counterroll assumed that static eye position was controlled by direct brainstem pathways from the vestibular nuclei via the ocular motor nuclei to the extraocular eye muscles. However, recent experim ental evidence has shown that the interstitial nucleus of Cajal (INC), know n as the vertical-torsional velocity-to-position integrator, plays a crucia l role in torsional otolith-dependent eye position, i.e. for the modificati on of Listing's plane by static head tilts. To evaluate possible mechanisms by which otolithic input may influence eye position via the INC, we constr ucted a 3D mathematical model of saccade and nystagmus generation, The mode l includes the burst generators located in the rostral interstitial nucleus of the medial longitudinal fasciculus (MLF) and paramedian pontine reticul ar formation and the velocity-to-position integrators located in the INC an d prepositus hypoglossi. The model simulations suggest that otolith pathway s to the neural integrator that adjust Listing's plane may involve the cere bellum.