Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-10T13:49:22.224Z Has data issue: false hasContentIssue false

Pharmacological isolation of visual cortical input to the cat accessory optic system: Effects of intravitreal tetrodotoxin on DTN unit responses

Published online by Cambridge University Press:  02 June 2009

Keith L. Grasse
Affiliation:
Department of Psychology and Biology, York University, North York, Ontario, Canada M3J 1P3

Abstract

Direction-selective responses were recorded from neurons in the dorsal terminal nucleus (DTN) of the cat accessory optic system before and after intravitreal injections of tetrodotoxin (TTX) into the contralateral eye. After approximately 100 min, direction-selective responses driven through stimulation of the contralateral, injected eye were reduced on average by 90%, while direction-selective responses driven through stimulation of the ipsilateral, uninjected eye were not significantly reduced. By 200 min postinjection, ipsilateral direction-selective responses were either equal to or sometimes greater than control values. In the final stages of these experiments (i.e. between 390–830 min after contralateral eye injections), ipsilateral eye responses were on average 30% higher than control. The effects of retinal blockade of the contralateral eye by TTX show that input from the ipsilateral eye alone is sufficient to mediate direction-selective responses in DTN cells. These results and those observed following bicuculline eye injections reported previously (Grasse et al. 1990) demonstrate that direction-selective responses in the DTN driven through stimulation of the contralateral and ipsilateral eyes arise from independent neural mechanisms located in the retina and visual cortex, respectively. Moreover, these findings also suggest that the contralateral eye exerts an inhibitory influence over ipsilateral eye responses which is diminished by TTX injections into the contralateral eye.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berman, A.L. (1968). The Brain Stem of the Cat: A Cytoarchitectonic Atlas with Stereotaxic Coordinates. Madison, Wisconsin: University of Wisconsin Press.Google Scholar
Berson, D.M. & Graybiel, A.M. (1980). Some cortical and subcortical fiber projections to the accessory optic nuclei in the cat. Neuroscience 5, 22032217.CrossRefGoogle Scholar
Collewijn, H. (1975). Oculomotor areas in the rabbit's midbrain and pretectum. Journal of Neurobiology 6, 322.CrossRefGoogle ScholarPubMed
Cynader, M.S. & Hoffmann, K.P. (1981). Strabismus disrupts binocular convergence in cat nucleus of the optic tract. Developmental Brain Research 1, 132136.CrossRefGoogle Scholar
Farmer, S.G. & Rodieck, R.W. (1982). Ganglion cells of the cat accessory optic system: morphology and retinal topography. Journal of Comparative Neurology 205, 190198.CrossRefGoogle ScholarPubMed
Grasse, K.L. & Cynader, M.S. (1984). Electrophysiology of lateral and dorsal terminal nuclei of the cat accessory optic system. Journal of Neurophysiology 51(2), 276293.CrossRefGoogle ScholarPubMed
Grasse, K.L. & Cynader, M.S. (1986). Response properties of single units in the accessory optic system of the dark-reared cat. Developmental Brain Research 27, 199210.CrossRefGoogle Scholar
Grasse, K.L. & Cynader, M.S. (1987). The accessory optic system of the monocularly deprived dat. Developmental Brain Research 31, 229241.CrossRefGoogle Scholar
Grasse, K.L. & Cynader, M.S. (1988). The effect of visual cortex lesions on vertical optokinetic nystagmus in the cat. Brain Research 455, 385389.CrossRefGoogle ScholarPubMed
Grasse, K.L. & Cynader, M.S. (1991). The accessory optic system of frontal-eyed animals. In Vision and Visual Dysfunction, Vol. IV, ed. Cronley-Dillon, , Chap. 5, pp. 111139. London: Macmillan.Google Scholar
Grasse, K.L., Ariel, M. & Smith, I.D. (1990 a). Direction-selective responses of units in the dorsal terminal nucleus of cat following intravitreal injections of bicuculline. Visual Neuroscience 4(6), 605617.CrossRefGoogle ScholarPubMed
Grasse, K.L., Ariel, M. & Smith, I. (1990 b). Pharmacological isolation of visual cortical input to the accessory optic system in cat: effects of intravitreal injections of bicuculline on DTN responses. Investigative Ophthalmology and Visual Science 31, Suppl ARVO Abstract p. 398.Google Scholar
Grasse, K.L., Cynader, M.S. & Douglas, R.M. (1984). Alterations in response properties in the lateral and dorsal terminal nuclei of the cat accessory optic system following visual cortex lesions. Experimental Brain Research 55, 6980.CrossRefGoogle ScholarPubMed
Hayhow, W.R. (1959). An experimental study of the accessory optic fiber system in the cat. Journal of Comparative Neurology 113, 281313.CrossRefGoogle ScholarPubMed
Hebb, D.O. (1949). Organization of Behavior. New York: John Wiley ' Sons.Google Scholar
Hoffmann, K.-P. (1989).Innate and learned components in a simple visuo-motor reflex. In Neural Computers, ed.Eckmiller, R. ' Von, Der Malsburg C., pp. 371380.Berlin: Springer-Verlag.CrossRefGoogle Scholar
Hoffmann, K.-P. & Schoppmann, A. (1981). A quantitative analysis of the direction-specific response of neurons in the cat's nucleus of the optic tract. Experimental Brain Research 42, 146157.CrossRefGoogle ScholarPubMed
Hoffmann, K.-P. & Schoppmann, A. (1975). Retinal input to direction-selective cells in the nucleus tractus opticus of the cat. Brain Research 99, 359366.CrossRefGoogle ScholarPubMed
Hoffmann, K.-P. (1982). Cortical versus subcortical contributions to the optokinetic reflex in the cat. In Functional Basis of Ocular Motility Disorders, ed. Lennerstrand, G., pp. 303310. Oxford: Pergamon.Google Scholar
Hoffmann, K.-P., Distler, C., Erickson, R.G. & Mader, W. (1988).Physiological and anatomical identification of the nucleus of the optic tract and dorsal terminal nucleus of the accessory optic tract in monkeys. Experimental Brain Research 69, 635644.CrossRefGoogle ScholarPubMed
Marcotte, R.R. & Updyke, B.V. (1982). Cortical visual areas of the cat project differentially Onto the nuclei of the accessory optic system. Brain Research 242, 205217.CrossRefGoogle ScholarPubMed
Schoppmann, A. (1985). Functional and developmental analysis of a visual corticopretectal pathway in the cat: a neuroanatomical and electrophysiological study. Experimental Brain Research 60, 363374.CrossRefGoogle Scholar
Simpson, J.I., Soodak, R.E. & Hess, R. (1979). The accessory optic system and its relation to the vestibulocerebellum. In Reflex Control of Posture and Movement, ed. Grant, R. & Pompeiano, O., pp.715724. Amsterdam: Elsevier.CrossRefGoogle Scholar