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Neurons of the medial terminal accessory optic nucleus of the rat are poorly collateralized

Published online by Cambridge University Press:  02 June 2009

R. J. Clarke
Affiliation:
Department of Anatomy and Neurobiology, California College of Medicine, University of California, Irvine Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Cidade Universitaria, Recife 50.000 PE, Brazil
R. A. Giolli
Affiliation:
Department of Anatomy and Neurobiology, California College of Medicine, University of California, Irvine
R. H. Blanks
Affiliation:
Department of Anatomy and Neurobiology, California College of Medicine, University of California, Irvine Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, California College of Medicine, University of California, Irvine
Y. Torigoe
Affiliation:
Department of Anatomy and Neurobiology, California College of Medicine, University of California, Irvine Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, California College of Medicine, University of California, Irvine
J. H. Fallon
Affiliation:
Department of Anatomy and Neurobiology, California College of Medicine, University of California, Irvine

Abstract

The vast majority of neurons of the rat medial terminal nucleus (MTN) project to the nucleus of the optic tract (NOT), but the MTN also projects to a lesser degree upon a number of other brainstem nuclei controlling optokinetic nystagmus. Because of the diversity of targets of the MTN, it is possible that individual neurons have branched axons that project to two or more brainstem nuclei. The possibility that axons of MTN-NOT neurons collateralize to innervate other MTN targets is examined in the rat with the fluorescent, double-labeling, retrograde tracer technique. Fluoro-Gold was injected into the NOT while Fast Blue was simultaneously injected into each of five other known targets of the MTN: the supraoculomotor-periaqueductal gray; the dorsal cap of the inferior olive; the visual tegmental relay zone; the dorsolateral nucleus of the basal pons; and the superior/lateral vestibular nuclei. Brainstem sections were processed for fluorescence microscopy and the MTN was examined for single- and double-labeled neurons. Results show that virtually all neurons of the MTN (>97.5%), together with neurons in the visual tegmental relay zone immediately surrounding the MTNd, are single-labeled in all paired injections involving the NOT and the other target nuclei. It was found that about 69% of MTN neurons project exclusively to the NOT, 5–10% project to each one of the other nuclei, and 3% of MTN neurons project to more than one target. Based upon cell counts from the fluorescent material, and previous analysis of Nissl-stained serial sections, the findings show that virtually all MTN neurons are projection neurons. It was concluded that the MTN is comprised of independent projection systems, possibly involved in different aspects of generating optokinetic nystagmus.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1989

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References

Biral, G.P., Porro, C.A., Cavazzuti, M., Benassi, C. & Corazza, R. (1987). Vertical and horizontal visual whole-field motion differently affect the metabolic activity of the rat medial terminal nucleus. Brain Research 412, 4353.CrossRefGoogle ScholarPubMed
Blanks, R.H.I., Giolli, R.A. & Pham, S.V. (1982). Projections of the medial terminal nucleus of the accessory optic system upon the pretectal nuclei in the pigmented rat. Experimental Brain Research 48, 228237.CrossRefGoogle ScholarPubMed
Fallon, J.H. (1981). Collateralization of monoamine neurons: meso-telencephalic dopamine projections to caudate, septum, and frontal cortex. Journal of Neuroscience 1, 13611368.CrossRefGoogle Scholar
Fallon, J.H. & Loughlin, S.E. (1982). Monoamine innervation of the forebrain: collateralization. Brain Research Bulletin 9, 295307.CrossRefGoogle ScholarPubMed
Giolli, R.A., Braithwaite, J.R. & Streeter, T.T. (1968). Golgi study of the nucleus of the transpeduncular tract in the rabbit. Journal of Comparative Neurology 133, 309328.CrossRefGoogle ScholarPubMed
Giolli, R.A., Blanks, R.H.I. & Torigoe, Y. (1984). Pretectal and brainstem projections of the medial terminal nucleus of the accessory optic system of the rabbit and rat as studied by anterograde and retrograde neuronal tracing methods. Journal of Comparative Neurology 227, 228251.CrossRefGoogle ScholarPubMed
Giolli, R.A., Blanks, R.H.I., Torigoe, Y. & Williams, D.D. (1985 a). Projections of the medial accessory optic nucleus, ventral tegmental nuclei, and substantia nigra of rabbit and rat as studied by retrograde axonal transport of horseradish peroxidase. Journal of Comparative Neurology 232, 99116.CrossRefGoogle ScholarPubMed
Giolli, R.A., Peterson, G.M., Ribak, C.E., McDonald, H.M., Blanks, R.H.I. & Fallon, J.H. (1985 b). GABAergic neurons comprise a major cell type in rodent visual relay nuclei: an immuno-cytochemical study of pretectal and accessory optic nuclei. Experimental Brain Research 61, 194203.CrossRefGoogle Scholar
Giolli, R.A., Torigoe, Y. & Blanks, R.H.I. (1988). Nonretinal projections to the medial terminal accessory optic nucleus in rabbit and rat: a retrograde and anterograde transport study. Journal of Comparative Neurology 269, 7386.CrossRefGoogle Scholar
Grasse, K.L. & Cynader, M.S. (1982). Electrophysiology of medial terminal nucleus of the accessory optic system in the cat. Journal of Neurophysiology 48, 490504.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, 276293.CrossRefGoogle ScholarPubMed
Kuypers, H.G.J.M., Catsman-Berrevoets, C.E. & Padt, R.E. (1977). Retrograde axonal transport of fluorescent substances in the rat's forebrain. Neuroscience Letters 6, 127135.CrossRefGoogle Scholar
Maekawa, K. & Simpson, J.I. (1973). Climbing fiber responses evoked in the vestibulo-cerebellum of rabbit from visual system. Journal of Neurophysiology 36, 649666.CrossRefGoogle Scholar
Magnin, M., Courjon, J.H. & Flandrin, J.M. (1983). Possible visual pathways to the cat vestibular nuclei involving the nucleus preposi-tus hypoglossi. Experimental Brain Research 51, 298303.CrossRefGoogle Scholar
Natal, C.L. & Britto, R.G. (1987). The pretectal nucleus of the optic tract modulates the direction selectivity of accessory optic neurons in rats. Brain Research 419, 320323.CrossRefGoogle ScholarPubMed
Ottersen, O.P. & Storm-Mathisen, J. (1984). GABA-containing neurons in the thalamus and pretectum of the rodent. Anatomy and Embryology 170, 197207.CrossRefGoogle ScholarPubMed
Penny, G.R., Conley, M., Schmechel, D.E. & Diamond, I.T. (1984). The distribution of glutamic acid decarboxylase immunoreactivity in the diencephalon of the opossum and rabbit. Journal of Comparative Neurology 228, 3856.CrossRefGoogle ScholarPubMed
Schmued, L.C. & Fallon, J.H. (1986). Fluoro-Gold: a new fluorescent retrograde axonal tracer with numerous unique properties. Brain Research 377, 147154.CrossRefGoogle ScholarPubMed
Simpson, J.I. (1984). The accessory optic system. Annual Review of Neuroscience 7, 1341.CrossRefGoogle ScholarPubMed
Simpson, J.I., Giolli, R.A. & Blanks, R.H.I. (1988). The pretectal nuclear complex and the accessory optic system. In Progress in Oculomotor Research — Vol. 2: Neuroanatomy of the Oculomotor System, ed. Buttner-Ennever, J., pp. 333362. Elsevier/North Holland Press, Amsterdam.Google Scholar
Torigoe, Y., Blanks, R.H.I., Giolli, R.A. & Fallon, J.H. (1983). Projections of the ventral midbrain tegmentum to the periaqueduc-tal gray (PAG) in the rabbit: visual oculomotor pathways from the medial terminal nucleus (MTN) of the accessory optic system. Society for Neuroscience Abstracts 9, 1089.Google Scholar
Walley, R.E. (1967). Receptive fields in the accessory optic system. Experimental Neurology 17, 2743.CrossRefGoogle ScholarPubMed
Weber, J.T. (1985). Pretectal complex and the accessory optic system of primates. Brain, Behavior, and Evolution 26, 117140.CrossRefGoogle ScholarPubMed