Summary
Pallido-thalamic transmission was studied by intracellular recording from neurons in the ventrolateral (VL) and ventroanterior (VA) nuclei of the thalamus in cats anesthetized with pentobarbital. Stimulation of the entopeduncular nucleus (ENT) produced short latency, inhibitory postsynaptic potentials in the VL-VA neurons (1.60 ms on average). When stimuli were applied closer to the VL-VA region along the pallido-thalamic pathway, i.e., to the rostral Forel's field, the IPSP latency was significantly reduced. Linear regression analysis of the IPSP latency against conduction distance between different stimulating and recording positions indicated that the IPSP was produced through a monosynaptic pathway at a conduction velocity of 5 to 11 m/s.
The neurons which received IPSPs from the ENT distributed in the rostromedial VL and in the rostral VA, whereas relay cells responding only to the contralateral brachium conjunctivum were found in the caudal VL and in the dorsolateral portion of the rostral VL-VA complex. Reciprocal convergence of pallidal and cerebellar impulses were observed in only a small number of cells, which were located in the border between the two neuron groups.
Recording of extracellular field potentials and focal stimulation within and around the rostral VL also indicated that the fiber potentials arose from the ENT nucleus and propagated along a bundle of fibers which terminated within the rostromedial VL-VA complex. These results are all explicable by assuming that the entopeduncular neurons are inhibitory in nature and so inhibit thalamic neurons monosynaptically.
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References
Angaut, P.: The ascending projections of the nucleus interpositus posterior of the cat cerebellum: An experimental anatomical study using silver impregnation methods. Brain Res 24, 377–394 (1970)
Carpenter, M.B., Strominger, N.L.: Efferent fibers of the subthalamic nucleus in the monkey. A comparison of the efferent projections of the subthalamic nucleus, substantia nigra and globus pallidus. Am J Anat 121, 41–72 (1967)
Cohen, D., Chambers, W.W., Sprague, J.M.: Experimental study of the efferent projections from the cerebellar nuclei to the brainstem of the cat. J Comp Neurol 109, 233–259 (1958)
Desiraju, T., Purpura, D.P.: Synaptic convergence of cerebellar and lenticular projections to thalamus. Brain Res 15, 544–547 (1969)
Dormont, J.F., Ohye, C.: Entopeduncular projection to the thalamic ventrolateral nucleus of the cat. Exp Brain Res 12, 254–264 (1971)
Eccles, J.C.: The physiology of synapses, pp. 1–270. Berlin, Göttingen, Heidelberg, New York: Springer 1964
Fox, C.A., Hillman, D.E., Siegesmund, K.A., Sether, L.A.: The primate globus pallidus and its feline and avian homologues: a Golgi and electron microscopic study. In: Evolution of the Forebrain. Hassler, R. and Stephan, H. (eds.), pp. 237–248. Stuttgart: Thieme 1966
Fox, C.A., Schmitz, J.T.: The substantia nigra and the entopenduncular nucleus in the cat. J Comp Neurol 80, 323–334 (1944)
Frigyesi, T.L., Machek, J.: Basal ganglia-diencephalon synaptic relations in the cat. I. An intracellular study of dorsal thalamic neurons during capsular and basal ganglia stimulation. Brain Res 20, 201–217 (1970)
Grofová, I.: Ansa and fasciculus lenticularis of carnivora. J Comp Neurol 138, 195–208 (1970)
Grofová, I., Rinvik, E.: Cortical and pallidal projections to the nucleus ventralis lateralis thalami. Electron microscopical studies in the cat. Anat Embryol (Berl.) 146, 113–132 (1974)
Hassler, R.: Thalamic regulation of muscle tone and the speed of movements. In: The Thalamus. Purpura, D.P. and Yahr, M.D. (eds.), pp. 419–436. New York: Columbia University Press 1966
Jasper, H., Ajmone-Marsan, C.: A stereotaxic atlas of the diencephalon of the cat. University of Toronto Press, published by The National Research Council of Canada 1954
Kemp, J.M., Powell, T.P.S.: The connexions of the striatum and globus pallidus: synthesis and speculation. Philos Trans R Soc Lond [Biol] 262, 441–157 (1971)
Kievit, J., Kuypers, H.G.J.M.: Fastigial cerebellar projections to the ventrolateral nucleus of the thalamus and the organization of the descending pathways. In: Cortico-thalamic projections and sensorimotor activities. Frigyesi, T., Rinvik, E., Yahr, M.D. (eds.), pp. 91–114. New York: Raven Press 1972
Kim, R., Nakano, K., Jayaraman, A., Carpenter, M.B.: Projections of the globus pallidus and adjacent structures: an autoradiographic study in the monkey. J Comp Neurol 169, 263–289 (1976)
Kuo, J.S., Carpenter, M.B.: Organization of pallido-thalamic projections in the rhesus monkey. J Comp Neurol 151, 201–236 (1973)
Kusama, T., Mabuchi, M., Sumino, T.: Cerebellar projections to the thalamic nuclei in monkeys. Proc Japan Acad 47, 505–510 (1971)
Mehler, W.R.: Idea of a new anatomy of the thalamus. J Psychiatr Res 8, 203–217 (1971)
Nauta, W.J.H., Mehler, W.R.: Some efferent connections of the lentiform nucleus in monkey and cat. Anat Rec 139, 260 (1961)
Nauta, W.J.H., Mehler, W.R.: Projections of the lentiform nucleus in the monkey. Brain Res 1, 3–42 (1966)
Olszewski, J.: The thalamus of the Macaca Mulatta. An Atlas for use with the stereotaxic instrument, p. 93. Basel, New York: Karger 1952
Rinvik, E.: A re-evaluation of the cytoarchitecture of the ventral nuclear complex of the cat's thalamus on the basis of cortico-thalamic connections. Brain Res 8, 237–254 (1968)
Snider, R.S., Niemer, W.T.: A Stereotaxic Atlas of the Cat Brain. Chicago: University of Chicago Press 1961
Szabo, J.: Projections from the body of caudate nucleus in the Rhesus monkey. Exp Neurol 27, 1–15 (1970)
Uchizono, K.: Characteristics of excitatory and inhibitory synapses in the central nervous system of the cat. Nature 207, 642–643 (1965)
Uno, M., Yoshida, M., Hirota, I.: The mode of cerebello-thalamic relay transmission investigated with intracellular recording from cells of the ventrolateral nucleus of cat's thalamus. Exp Brain Res 10, 121–139 (1970)
Uno, M., Yoshida, M.: Monosynaptic inhibition of thalamic neurons produced by stimulation of the pallidal nucleus in cats. Brain Res 99, 377–380 (1975)
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Uno, M., Ozawa, N. & Yoshida, M. The mode of pallido-thalamic transmission investigated with intracellular recording from cat thalamus. Exp. Brain Res. 33, 493–507 (1978). https://doi.org/10.1007/BF00235570
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DOI: https://doi.org/10.1007/BF00235570