Topographical organization of cortical efferent zones projecting to distal forelimb muscles in the monkey
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The functional organization of a cortical efferent system controlling contralateral distal forelimb muscles was examined in monkeys using the method of intracortical microstimulation (ICMS). The results obtained are:
Thresholds of stimulation for producing contraction of contralateral distal forelimb muscles were much lower (less than 1/100) in the depth of the cortex than on the surface.
These low threshold spots were confined to a small region of the cortex (hand area) and ICMS with the same strength in the neighboring cortex did not produce contraction from any part of the body.
Low threshold spots for a given movement were distributed along the direction of radial fibers within the gray matter constituting a columnar shape.
Within a given columnar efferent zone, the thresholds were lower in the deep layer (V) than in the superficial layers.
Each efferent zone had a sharp boundary, and frequently overlapped with another efferent zone which produced an opposite movement.
Efferent zones controlling various movements of a joint were located close together and zones projecting to proximal muscles were located more rostrally than those projecting to distal muscles.
These efferent zones constitute a fine mosaic organization within the depth of the cortex and functional significance of the organization was discussed in relation to the pyramidal tract.
Key wordsMotor cortex Monkey Microstimulation
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- Asanuma, H., Sakata, H.: Functional organization of a cortical efferent system examined with focal depth stimulation in cats. J. Neurophysiol.30, 35–54 (1967).Google Scholar
- —, Stoney, S.D., Jr., Abzug, C.: Relationship between afferent input and motor outflow in cat motorsensory cortex. J. Neurophysiol.31, 670–681 (1968).Google Scholar
- — —, Thompson, W.D.: Characteristics of cervical interneurones which mediate cortical motor outflow to distal forelimb mucsles in cats. Brain Res.27, 79–95 (1971).Google Scholar
- —, Ward, J.E.: Patterns of contraction of distal forelimb muscles produced by intracortical stimulation in cats. Brain Res.27, 97–109 (1971).Google Scholar
- Brooks, V.B., Asanuma, H.: Recurrent cortical effects following stimulation of medullary pyramid. Arch. ital. Biol.103, 247–278 (1965).Google Scholar
- Davies, P.W.: Chamber for microelectrode studies in the cerebral cortex. Science124, 179–180 (1956).Google Scholar
- Denny-Brown, D.: Motor mechanisms-Introduction: The general principles of motor integration. In: Handbook of Physiology. Amer. Physiol. Soc. Vol. 2, pp. 781–796 1960.Google Scholar
- Fritch, G., Hitzig, E.: Über die elektrische Erregbarkeit des Großhirns. Arch. anat. Physiol. wiss. Med.37, 300–332 (1870).Google Scholar
- Fulton, J.F.: Physiology of the nervous system, pp. 392–420. New York: Oxford University Press 1949.Google Scholar
- Glees, P., Cole, J.: Recovery of skilled motor functions after small repeated lesions of motor cortex in macaque. J. Neurophysiol.13, 137–148 (1950).Google Scholar
- Hern, J.E.C., Phillips, J.C., Porter, R.: Electrical thresholds of unimpaled corticospinal cells in the cat. Quart. J. exp. Physiol.47, 134–140 (1962).Google Scholar
- Kennard, M.A.: Reorganization of motor function in the cerebral cortex of monkeys deprived of motor areas in infancy. J. Neurophysiol.1, 477–496 (1938).Google Scholar
- Klüver, H., Barrera, E.: A method for the combined staining of cells and fibers in the nervous system. J. Neuropath. exp. Neurol.12, 400–403 (1953).Google Scholar
- Kuypers, H., Brinkman, J.: Precentral projections to different parts of the spinal intermediate zone in the Rhesus monkey. Brain Res.24, 29–48 (1970).Google Scholar
- Landgren, S., Phillips, C.G., Porter, R.: Cortical fields of origin of the monosynaptic pyramidal pathways to some alpha motoneurones of the baboon's hand and forearm. J. Physiol. (Lond.)161, 112–125 (1962).Google Scholar
- Lawrence, D.G., Kuypers, G.H.J.M.: The functional organization of the motor system in the monkey. I. The effects of bilateral pyramidal lesions. Brain91, 1–14 (1968).Google Scholar
- Liddell, E.G.T., Phillips, C.G.: Thresholds of cortical representation. Brain73, 125–140 (1950).Google Scholar
- Liu, C.N., Chambers, W.W.: An experimental study of the cortico-spinal system in the monkey (Macaca mulatta): The spinal pathways and preterminal distribution of degenerating fibers following discrite lesions of the pre- and postcentral gyri and bulbar pyramid. J. comp. Neurol.123, 257–284 (1964).Google Scholar
- Phillips, C.G.: Motor apparatus of the baboon's hand. Proc. roy. Soc. B.173, 141–174 (1969).Google Scholar
- Rosén, I., Asanuma, H.: Organization of the projection from motor cortex to distal forelimb muscles in the monkey. Proc. XXV int. Congr. Physiol. Sci.9, 411 (1971).Google Scholar
- — —: Peripheral afferent inputs to the forelimb area of the monkey motor cortex: Input-output relations. Exp. Brain Res.14, 257–273 (1972).Google Scholar
- Sherrington, C.S.: On nerve-tracts degenerating secondarily to lesions of the cortex cerebri. J. Physiol. (Lond.)10, 429–432 (1889).Google Scholar
- Sholl, D.A.: A comparative study of the neuronal packing density in the cerebral cortex. J. Anat. (Lond.)93, 143–158 (1959).Google Scholar
- Stoney, S.D., Jr., Thompson, W.D., Asanuma, H.: Excitation of pyramidal tract cells by intracortical microstimulation: Effective extent of stimulating current. J. Neurophysiol.31, 659–669 (1968).Google Scholar
- Takahashi, K., Kubota, K., Uno, M.: Recurrent facilitation in cat pyramidal cells. J. Neurophysiol.30, 22–34 (1967).Google Scholar
- Tower, S.S.: Pyramidal lesion in the monkey. Brain63, 36–90 (1940).Google Scholar