Ocular torsion produced by unilateral chemical inactivation of the interstitial nucleus of Cajal in chronically labyrinthectomized cats

Unilateral lesions of the rostral midbrain involving the interstitial nucleus of Cajal (INC) have been known to produce ocular torsion in alert animals including humans, which has been assumed to be the result of an impaired otolith-ocular reflex. We examined the effects of chemical deactivation of the INC using a gamma-aminobutyric acid (GABA) agonist (muscimol) in cats that had received bilateral labyrinthectomy, and compared the results with those in normal cats. Ocular torsion with a magnitude similar to that observed in normal cats appeared in chronically labyrinthectomized cats after unilateral muscimol infusion into the INC, indicating that ocular torsion following unilateral INC deactivation can be produced by a mechanism independent of the otolith-ocular reflex.

[1]  Kikuro Fukushima,et al.  The interstitial nucleus of Cajal in the midbrain reticular formation and vertical eye movement , 1991, Neuroscience Research.

[2]  W. Graf,et al.  The Vertical Vestibulo-Ocular Reflex , 1982 .

[3]  T. Brandt,et al.  Tonic contraversive ocular tilt reaction due to unilateral meso‐diencephalic lesion , 1990, Neurology.

[4]  G Westheimer,et al.  The ocular tilt reaction--a brainstem oculomotor routine. , 1975, Investigative ophthalmology.

[5]  K. Fukushima,et al.  The interstitial nucleus of Cajal and its role in the control of movements of head and eyes , 1987, Progress in Neurobiology.

[6]  John H. Anderson,et al.  OCULAR TORSION IN THE CAT AFTER LESIONS OF THE INTERSTITIAL NUCLEUS OF CAJAL * , 1981, Annals of the New York Academy of Sciences.

[7]  The origin of high and regular discharge rates of eye-movement-related neurons in the region of the interstitial nucleus of Cajal , 1991, Neuroscience Research.

[8]  G S Brindley,et al.  A case of ocular tilt reaction and torsional nystagmus due to direct stimulation of the midbrain in man. , 1991, Brain : a journal of neurology.

[9]  T. Vilis,et al.  Generation of torsional and vertical eye position signals by the interstitial nucleus of Cajal , 1991, Science.

[10]  K. Fukushima,et al.  Activity of eye-movement-related neurons in the region of the interstitial nucleus of Cajal during sleep , 1990, Neuroscience Research.

[11]  R. Leigh,et al.  The neurology of eye movements , 1984 .

[12]  M. Gresty,et al.  Ocular tilt reaction with peripheral vestibular lesion , 1979, Annals of neurology.

[13]  A. Fuchs,et al.  Vertical eye movement-related responses of neurons in midbrain near intestinal nucleus of Cajal. , 1981, Journal of neurophysiology.