Anatomy and Physiology of the Subthalamic Nucleus: A Driving Force of the Basal Ganglia
The subthalamic (STh) nucleus is located between the zona incerta dorsally and the cerebral peduncle ventrally. The morphological features of STh neurons have been studied extensively at the light microscopic level (Rafols and Fox, 1976; Iwahori, 1978; Yelnik and Percheron, 1979; Hammond and Yelnik, 1983; Kita et al., 1983b; Afsharpour, 1985b) and the electron microscopic level (Rafols and Fox, 1976; Hassler et al., 1982; Chang et al., 1983). Although these studies have proposed different classification schemes for STh neurons, there is an almost complete concensus with regard to the somatic and dendritic morphology of the principal STh neurons in various species. STh neurons are stellate neurons with radiating and sparsely spined dendrites. Ultrastructure studies have demonstrated that the somata of STh neurons contain abundant organelles with nuclei that have deeply invaginated nuclear envelopes and pale nucleoplasm with little heterochromatin. In the neuropil, at least two types of axon terminals were identified. One type of terminal (Gray’s Type I) contained medium-sized round vesicles and formed asymmetrical synapses. The other type of terminal (Gray’s Type II) was large and contained both round and flattened vesicles and formed adherens junctions and symmetrical synapses.
KeywordsSubstantia Nigra Globus Pallidus Subthalamic Nucleus Cerebral Peduncle Zona Incerta
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- Bak, I.J., Choi, W.B., Hassler, R., Usunoff, K.G., and Wagner, A., 1975, Fine structural synaptic organization of the corpus striatum and substantia nigra in rat and cat, in: “Advances in Neurology, Vol. 9,” D.B. Calne, T.N. Chase, and A. Barbeau, eds., Raven Press, New York, pp.25–41.Google Scholar
- DeLong, M.R. and Alexander, G.E., 1986, Organization of basal ganglia, in: “Diseases of the Nervous System,” A.D. Asbury, G.M. McKhann and W.I. McDonald, eds., W.B. Sanders Co., Philadelphia.Google Scholar
- Deniau, J.M., Hammond, C., Chevalier, G. and Feger, J., 1978, Evidence for branched subthalamic nucleus projections to substantia nigra, entopeduncular nucleus and globus pallidus, Neurosci. Letters, 9:117–121.Google Scholar
- Fox, C.A. and Rafols, J.A., 1976, The striatal efferents in the globus pallidus and in the substantia nigra, in: “The Basal Ganglia,” M.D. Yahr, ed., Raven Press, New York, pp. 37–55.Google Scholar
- Grofova, I., 1979, Extrinsic connections of the neostriatum, in: “The Neostriatum,” I. Divac and G.E. Oberg, eds., Pergamon Press, New York, pp. 37–51.Google Scholar
- Hammond, C., Shibazaki, T. and Rouzaire-Dubois, B., 1983, Branched output neurons of the rat subthalamic nucleus: Electrophysiological study of the synaptic effects on identified cells on the two main target nuclei, the entopeduncular nucleus and the substantia nigra, Neuroscience, 9:511–520.PubMedCrossRefGoogle Scholar
- Kita, H. and Kitai, S.T., 1987, Efferent projections of the subthalamic nucleus in the rat: Light and electron microscopic analysis with the PHA-L method, J. Comp. Neurol., In press.Google Scholar
- Nauta, W.J.H. and Domesick, V.B., 1984, Afferent and efferent relationships of the basal ganglia, in: “Functions of the Basal Ganglia,” D. Evered and M. O’Connor, eds., Pitman Press, Bath, pp. 3–29.Google Scholar
- Percheron, G., Yelnik, J. and Francois, C., 1984, The primate striato-pallido-nigral system: An integrative system for cortical information, in: “The Basal Ganglia, Structure and Function,” J.S. McKenzie, R.E. Kimm and L.N. Wilcock, eds., Plenum Press, New York, pp. 87–107Google Scholar
- Rinvik, E., Grofova, I., Hammond, C. and Deniau, J.M., 1979, A study of the afferent connections to the subthalamic nucleus in the monkey and the cat using the horseradish peroxidase technique, Adv. Neurol., 24:53–69.Google Scholar
- VanderMaelen, C.P. and Kitai, S.T., 1980, Intracellular analysis of synaptic potentials in rat neostriatum following stimulation of the cerebral cortex, thalamus, and substantia nigra, Brain Res. Bull., 5:725–733.Google Scholar
- Wilson, C.J., 1985, Postsynaptic potentials evoked in spiny neostriatal neurons by stimulation of ipsilateral and contralateral neocortex, Brain Res., 367:210–213.Google Scholar