Abstract
-
1.
The effects of various brain lesions on the responses of vestibular nuclear neurons (Vn) of the horizontal semicircular canal system to optokinetic stimulations were studied to elucidate the optokinetic path from the retina to the vestibular nuclei. A previous study performed in intact rats served as a control [2].
-
2.
It was shown that the pretectal region including the n. of the optic tract is the first central relay in the optokinetic path; it receives its functionally effective input from the contralateral eye. Unilateral lesions of this area rendered all Vn responses unidirectional when tested with binocular stimulation. Lesions of other visual centers such as the superior colliculi or visual cortices had no influence on the optokinetic response properties of Vn.
-
3.
The area of the n. reticularis tegmenti pontis (NRTP) proved to be an important link between pretectum and vestibular nuclei: Unilateral lesions produced effects similar to those described for pretectal lesions. Pretectal axons to NRTP descend lateral to the MLF and tectospinal tract.
-
4.
It was demonstrated that the vestibular commissure plays the crucial role in mediating the mirror image optokinetic effects to Vn on the opposite side and assures the bidirectionality of the responses to binocular stimulation.
-
5.
Cerebellectomy did not significantly affect the Vn responses to the optokinetic stimuli presented in this study.
-
6.
Electrical stimulation of the pretectum excited type II and inhibited type I Vn ipsilaterally and had the opposite effect on Vn located on the opposite side. NRTP stimulation excited type II and inhibited type I ipsilaterally; latency analysis of these effects suggested that the pretectal stimuli excited ipsilateral NRTP neurons which, in turn, excited ipsilateral type II Vn. Ipsilateral type I inhibition as well as the concurrent contralateral type II inhibition and type I excitation are produced by the inhibitory action of type II on type I and the commissural system.
-
7.
Systemic application of picrotoxin abolished all optokinetic responses of Vn except the type II activation. This finding further supports the hypothesis described above.
-
8.
Unilateral pretectal or NRTP lesions abolished OKN to surround motion in the direction of the lesion.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Berman, N.: Connections of the pretectum in the cat. J. Comp. Neurol.174, 227–254 (1977)
Cazin, L., Precht, W., Lannou, J.: Optokinetic responses of vestibular nucleus neurons in the rat. Pflügers Arch.384, 31–38 (1980)
Collewijn, H.: Oculomotor areas in the rabbit's midbrain and pretectum. J. Neurobiol.6, 3–22 (1975a)
Collewijn, H.: Direction-selective units in the rabbit's nucleus of the optic tract. Brain Res.100, 489–508 (1975b)
Hayhow, W. R., Sefton, A., Webb, C.: Primary optic centers of the rat in relation to the terminal distribution of the crossed and uncrossed optic nerve fibers. J. Comp. Neurol.118, 295–308 (1962)
Hellstrøm-Hoddevik, G., Brodal, A., Walberg, F.: The reticulovestibular projection in the cat. An experimental study with silver impregnation methods. Brain Res.94, 383–399 (1975)
Hoffmann, K.-P., Schoppmann, A.: Retinal input to direction selective cells in the nucleus tractus opticus of the cat. Brain Res.99, 359–366 (1975)
Keller, E. L., Precht, W.: Visual-vestibular responses in vestibular nuclear neurons in intact and cerebellectomized, alert cat. Neuroscience4, 1599–1613 (1979)
Kravitz, E. A.: Acetylcholine, γ-aminobutyric acid, and glutamic acid. In: Physiological and chemical studies related to their roles as neurotransmitter agents (G. C. Quarton, T. Melnechuk, F. O. Schmitt, eds.), pp. 433–444. New York: Rockefeller Univ. Press 1967
Markham, C. H., Precht, W., Shimazu, H.: Effect of stimulation of interstitial nucleus of Cajal on vestibular unit activity in the cat. J. Neurophysiol.29, 493–507 (1966)
Pellegrino, L. J., Cashman, A. J.: A stereotaxic atlas of the rat brain. New York: Appleton-Century-Crofts 1967
Precht, W., Cazin, L.: Functional deficits in the optokinetic system of albino rats. Exp. Brain Res.37, 183–186 (1979a)
Precht, W., Cazin, L.: Pathways mediating optokinetic responses of rat central vestibular neurons. Pflügers Arch., Suppl.382, 191 (1979b)
Precht, W., Strata, P.: Pathways mediating optokinetic responses of cat's vestibular neurons. Neurosc. Lett., Suppl.3, 351 (1979)
Precht, W., Schwindt, P. C., Baker, R.: Removal of vestibular commissural inhibition by antagonists of GABA and glycine. Brain Res.62, 222–226 (1973)
Scalia, F.: The termination of retinal axons in the pretectal region of mammals. J. Comp. Neurol.145, 223–258 (1972)
Shimazu, H., Precht, W.: Inhibition central vestibular neurons from the contralateral labyrinth and its mediating pathway. J. Neurophysiol.29, 467–492 (1966)
Tauber, E. S., Atkin, A.: Optomotor responses to monocular stimulation: relation to visual system organization. Science160, 1365–1367 (1968)
Terasawa, K., Otani, K., Yamada, J.: Descending pathways of the nucleus of the optic tract in the rat. Brain Res.173, 405–417 (1979)
Waespe, W., Henn, V.: Conflicting visual-vestibular stimulation and vestibular nucleus activity in alert monkey. Exp. Brain Res.33, 203–211 (1978)
Wood, C. C., Spear, P. D., Braun, J. J.: Direction-specific deficits in horizontal optokinetic nystagmus following removal of visual cortex in the cat. Brain Res.60, 231–237 (1973)
Author information
Authors and Affiliations
Additional information
Supported by a fellowship from the Max Planck Society
Rights and permissions
About this article
Cite this article
Cazin, L., Precht, W. & Lannou, J. Pathways mediating optokinetic responses of vestibular nucleus neurons in the rat. Pflugers Arch. 384, 19–29 (1980). https://doi.org/10.1007/BF00589510
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00589510