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Does the reticular thalamic nucleus project to the midbrain?

  • Published:
Journal of Neurocytology

Abstract

In this study, we investigated whether the reticular thalamic nucleus has a projection to major centres of the midbrain in rats, rabbits and cats. Various tracers (biotinylated dextran, cholera toxin B subunit, fluorescent latex beads) were injected either into the midbrain tectum (deep layers of the superior colliculus) or tegmentum (midbrain reticular and pedunculopontine nuclei). In other experiments, different coloured latex beads (red and green) were injected into the deep layers of the superior colliculus and into the midbrain reticular nucleus of the same animal (rabbits). Our major finding is that in rats, rabbits and cats, there are no retrogradely labelled cells in the reticular thalamic nucleus after tracer injections into the abovementioned midbrain centres. In rabbits and cats, however, there are retrogradely labelled cells lying close to the ventromedial edge of the reticular thalamic nucleus after such injections. We show, by means of immunocytochemical double-labelling, that these retrogradely labelled cells do not lie in the reticular thalamic nucleus as suggested by previous studies, but in the inner small-celled region, a group of small cells that forms part of the zona incerta. Although there appears to be no clear topography of projection of the inner small-celled region, our tracer double-labelling experiments show that separate cells in the inner small-celled region project to individual centres of the midbrain (i.e., there are very few double-labelled cells after double injections). In rats, unlike in rabbits and cats, there is no clearly defined inner small-celled region and there are no retrogradely labelled cells seen along the ventromedial edge of the reticular thalamic nucleus. Our results suggest that in rats, rabbits and cats, there is no projection of the reticular thalamic nucleus to major centres of the midbrain, suggesting that the nucleus may not have a very strong influence on midbrain function, as it does on dorsal thalamic function.

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References

  • ANGELUCCI, A., CLASCAÀ, F. & SUR, M. (1996) Anterograde axonal tracing with the subunit B of cholera toxin: a highly sensitive immunohistochemical protocol for revealing fine axonal morphology in adult and neonatal brains. Journal of Neuroscience Methods 65, 101-12.

    Google Scholar 

  • BERMAN, A. L. & JONES, E. G. (1982) The Thalamus and Basal Telencephalon of the Cat. A Cytoarchitectonic Atlas with Stereotaxic Coordinates. Madison: University of Wisconsin Press.

    Google Scholar 

  • BERRY, D. J., OHARA, P. T., JEFFREY, G. & LIEBERMAN, A. R. (1986) Are there any connections between the thalamic reticular nucleus and the brainstem reticular formation? Journal of Comparative Neurology 243, 347-62.

    Google Scholar 

  • CLEMENCE, A. E. & MITROFANIS, J. (1992) Cytoarchitectonic heterogeneities in the thalamic reticular nucleus of cats and ferrets. Journal of Comparative Neurology 322, 167-81.

    Google Scholar 

  • COLEMAN, K. A. & MITROFANIS, J. (1996) Organisation of the visual reticular thalamic nucleus of the rat. European Journal of Neuroscience 8, 388-404.

    Google Scholar 

  • CRABTREE, J. W. (1992) Somatotopic organisation within the cat's thalamic reticular nucleus. European Journal of Neuroscience 4, 1352-61.

    Google Scholar 

  • CRABTREE, J. W. (1996) Organisation in the somatosensory sector of the cat's thalamic reticular nucleus. Journal of Comparative Neurology 366, 207-22.

    Google Scholar 

  • CRABTREE, J. W. & KIND, P. C. (1993) Monoclonal antibody Cat-301 selectively identifies a subset of nuclei in the cat's somatosensory thalamus. Journal of Neurocytology 22, 903-12.

    Google Scholar 

  • EDWARDS, S.B., GINSBURGH, C. L., HENKEL, C. K. & STEIN, B. E. (1979) Sources of subcortical projections to the superior colliculus in the cat. Journal of Comparative Neurology 1184, 309-30.

    Google Scholar 

  • GIRIS, M. & SHIH-CHANG, W. (1981) Stereotaxic Atlas of the Rabbit Brain. St. Louis: Warren H. Green.

    Google Scholar 

  • GROFOVÀ, I., OTTERSON, O. P. & RINVIK, E. (1978) Mesencephalic and diencephalic afferents to the superior colliculus and periaqueductal grey substance demonstrated by retrograde axonal transport of horseradish peroxidase in the cat. Brain Research 146, 205-20.

    Google Scholar 

  • HOUSER, C. R., VAUGHN, J. E., BARBER, R. P. & ROBERTS, E. (1980) GABA neurones are the major cell type of the nucleus reticularis thalami. Brain Research 200, 341-54.

    Google Scholar 

  • JONES, E. G. (1975) Some aspects of the organisation of the thalamic reticular complex. Journal of Comparative Neurology 162, 285-308.

    Google Scholar 

  • JONES, E. G. (1985) The Thalamus. New York: Plenum Press.

    Google Scholar 

  • KIM, U., GREGORY, E. & HALL, W. C. (1992) Pathway from the zona incerta to the superior colliculus in the rat. Journal of Comparative Neurology 321, 555-75.

    Google Scholar 

  • LIN, R. C., NICOLELIS, M. A., SCHNEIDER, J. S. & CHAPIN, J. K. (1990) A major GABAergic pathway from zona incerta to neocortex. Science 248, 1553-56.

    Google Scholar 

  • LUPPI, P-H., FORT, P. & JOUVET, M. (1990) Iontophoretic application of unconjugated cholera toxin B subunit (CTb) combined with immunohistochemistry of neurochemical substances: a method for transmitter identification of labelled neurones. Brain Research 534, 209-24.

    Google Scholar 

  • MIHAILOFF, G. A. (1995) Orthograde axonal transport of projections from the zona incerta and pretectum to the basilar pontine nuclei in the rat. Journal of Comparative Neurology 360, 301-18.

    Google Scholar 

  • MINDERHOUD, J. M. (1971) An anatomical study of the efferent connections of the thalamic reticular nucleus. Experimental Brain Research 12, 435-46.

    Google Scholar 

  • MITROFANIS, J. (1992) Patterns of antigenic expression in the thalamic reticular nucleus of developing rats. Journal of Comparative Neurology 320, 161-81.

    Google Scholar 

  • MITROFANIS, J. & GUILLERY, R. W. (1993) New views of the thalamic reticular nucleus in the adult and the developing brain. Trends in Neuroscience 16, 240-5.

    Google Scholar 

  • MORELL, J. I., GREENBERGE, L. M. & PFAFF, D. W. (1981) Hypothalamic, other diencephalic and telencephalic neurones that project to the dorsal midbrain. Journal of Comparative Neurology 201, 589-620.

    Google Scholar 

  • NICOLELIS, M. A., CHAPIN, J. K. & LIN, R. C. (1992) Somatopic maps within the zona incerta relay parallel GABAergic somatosensory pathways to the neocortex, superior colliculus and brainstem. Brain Research 577, 134-41.

    Google Scholar 

  • OHARA, P. T. & LIEBERMAN, A. R. (1985) The thalamic reticular nucleus of the adult rat: experimental anatomical analysis. Journal of Neurocytology 14, 365-411.

    Google Scholar 

  • PARENT, A. & STERIADE, M. (1984) Midbrain tegmental projections of nucleus reticularis thalami of cat and monkey: a retrograde transport and antidromic invasion study. Journal of Comparative Neurology 229, 548-58.

    Google Scholar 

  • PAXINOS, G. & WATSON, C. J. (1986) The Rat Brain in Stereotaxic Coordinates. Second Edition. Sydney: Academic Press.

    Google Scholar 

  • RAJAKUMAR, N., ELISEVICH, K. & FLUMERFELT, B. A. (1993) Biotinylated dextran: a versatile anterograde and retrograde neuronal tracer. Brain Research 607, 47-53.

    Google Scholar 

  • RIECK, R. W., HUERTA, M. F., HARTING, J. K. & WEBER, J. T. (1986) Hypothalamic and ventral thalamic projections to the superior colliculus in the cat. Journal of Comparative Neurology 243, 249-65.

    Google Scholar 

  • RINVIK, E. & WIBERG, M. (1990) Demonstration of reciprocal connection between the periaqueductal grey matter and the reticular thalamic nucleus of the thalamus. Anatomy and Embryology 181, 577-84.

    Google Scholar 

  • SCHEIBEL, M. E. & SCHEIBEL, A. B. (1966) The organisation of the nucleus reticularis thalami: a Golgi study. Brain Research 1, 43-62.

    Google Scholar 

  • SWANSON, L. W. (1992) Brain Maps: Structure of the Rat Brain. Amsterdam: Elsevier.

    Google Scholar 

  • TAYLOR, A. M., JEFFREY, G. & LIEBERMAN, A. R. (1986) Subcortical afferent and efferent connections of the superior colliculus in the rat and comparisons between albino and pigmented strains. Experimental Brain Research 62, 131-42.

    Google Scholar 

  • VACCARO, T. M. & MITROFANIS, J. (1996a) The reticular thalamic region of rabbits: organisation of efferents to the superior colliculus. Journal of Comparative Neurology 369, 209-19.

    Google Scholar 

  • VACCARO, T. M. & MITROFANIS, J. (1996b) Does the reticular thalamic nucleus project to the brainstem? Proceedings of the Australian Neuroscience Society 16, 190.

    Google Scholar 

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Vaccaro, T., Mitrofanis, J. Does the reticular thalamic nucleus project to the midbrain?. J Neurocytol 26, 223–239 (1997). https://doi.org/10.1023/A:1018540231486

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