Summary
Stimulation of the contralateral pyramid and intracellular recording from forelimb motoneurones was used to investigate corticomotoneuronal pathways in the cat.
A train of pyramidal volleys evokes short-latency EPSPs in flexor motoneurones and in many extensor motoneurones. The latency for the on-set after the effective pyramidal volley — usually the third — strongly indicates a disynaptic linkage. These disynaptic EPSPs were common in triceps motoneurones to fast heads but rare in those to slow heads.
Pyramidal IPSPs with a slightly longer latency, suggesting a trisynaptic linkage, were found in both flexor and extensor motoneurones. They were common in motoneurones to slow heads of triceps. Disynaptic pyramidal IPSPs were found only occasionally.
In addition pyramidal volleys may evoke late large EPSPs and/or IPSPs in any combination with the short-latency PSPs.
Similar content being viewed by others
References
Agnew, R.F., Preston, J.B., Whitlock, D.G.: Patterns of motor cortex effects on ankle flexor and extensor motoneurones in the “pyramidal” cat preparation. Exp. Neurol. 8, 247–263 (1963)
Alien, G.I., Tsukahara, N.: Cerebrocerebellar communication systems. Physiol. Rev. 54, 957–1006 (1974)
Andersen, H.T., Körner, L., Landgren, S., Silfvenius, H.: Fibre components and cortical projections of the elbow joint nerve in the cat. Acta physiol. scand. 69, 373–382 (1967)
Baldissera, F., Lundberg, A., Udo, M.: Stimulation of pre- and postsynaptic elements in the red nucleus. Exp. Brain Res. 15, 151–167 (1972)
Bruggencate, G. ten, Burke, R., Lundberg, A., Udo, M.: Interaction between the vestibulospinal tract, contralateral flexor reflex afferents and Ia afferents. Brain Res. 14, 529–532 (1969)
Burke, R.E.: On the central nervous system control of fast and slow twitch motor units. In: New Developments in Electromyography and Clinical Neurophysiology. Vol. 3 (ed. J.E. Desmedt), pp. 69–94. Basel: Karger 1973
Burke, R., Jankowska, E., Bruggencate, G. ten: A comparison of peripheral and rubrospinal synaptic input to slow and fast twitch motor units of triceps surae. J. Physiol. (Lond.) 207, 709–732 (1970)
Eccles, J.C., Eccles, R.M., Lundberg, A.: The action potentials of the alpha motoneurones supplying fast and slow muscles. J. Physiol. (Lond.) 142, 275–291 (1958)
Endo, K., Araki, T., Kawai, Y.: Contra- and ipsilateral cortical and rubral effects on fast and slow spinal motoneurones of the cat. Brain Res. 88, 91–98 (1975)
Gorska, T., Jankowska, E., Mossakowski, M.: Effects of pyramidotomy on instrumental conditioned reflexes in cats. I. Manipulatory reflexes. Acta Biol. exp. (Warszawa) 26, 441–450 (1966)
Granit, R., Burke, R.E.: The control of movement and posture. Brain Res. 53, 1–28 (1973)
Henneman, E., Somjen, G., Carpenter, D.O.: Functional significance of cell size in spinal motoneurons. J. Neurophysiol. 28, 560–580 (1965)
Hongo, T., Jankowska, E., Lundberg, A.: The rubrospinal tract. I. Effects on alpha-motoneurones innervating hindlimb muscles in cats. Exp. Brain Res. 7, 344–364 (1969)
Illert, M., Lundberg, A., Tanaka, R.: Disynaptic corticospinal effects in forelimb motoneurones in the cat. Brain Res. 75, 312–315 (1974)
Illert, M., Lundberg, A., Tanaka, R.: Integration in a disynaptic cortico-motoneuronal pathway to the forelimb in the cat. Brain Res. 93, 525–529 (1975a)
Illert, M., Lundberg, A., Padel, Y., Tanaka, R.: Convergence on propriospinal neurones which may mediate disynaptic corticospinal excitation to forelimb motoneurones in the cat. Brain Res. 93, 530–534 (1975b)
Illert, M., Lundberg, A., Tanaka, R.: Integration in descending motor pathways controlling the forelimb in the cat. II. Convergence on neurones mediating disynaptic cortico-motoneuronal excitation. Exp. Brain Res. 00, 000–000 (1976)
Jankowska, E., Lund, S., Lundberg, A., Pompeiano, O.: Inhibitory effects evoked through ventral reticulospinal pathways. Arch. ital. Biol. 106, 124–140 (1968)
Kostyuk, P.G.: Interneuronal mechanisms of interaction between descending and afferent signals in the spinal cord. In: Golgi Centennial Symposium. Proceedings (ed. M. Santini), pp. 247–259. New York: Raven Press 1975
Kostyuk, P.G., Vasilenko, D.A., Lang, E.: Propriospinal pathways in the dorsolateral funiculus and their effects on lumbosacral motoneuronal pools. Brain Res. 28, 233–249 (1971)
Kuypers, H.G.J.M.: The anatomical organization of the descending pathways and their contribution to motor control especially in primates. In: New Developments in Electromyography and Clinical Neurophysiology. Vol. 3 (ed. J.E. Desmedt), pp. 38–68. Basel: Karger 1973
Llinás, R., Terzuolo, C.A.: Mechanisms of supraspinal actions upon spinal cord activities. Reticular inhibitory mechanisms on alpha-extensor motoneurons. J. Neurophysiol. 27, 579–591 (1964)
Lundberg, A., Voorhoeve, P.: Effects from the pyramidal tract on spinal reflex arcs. Acta physiol. scand. 56, 201–219 (1962)
Schmidt, R.F., Willis, W.D.: Intracellular recording from motoneurons of the cervical spinal cord of the cat. J. Neurophysiol. 26, 28–43 (1963)
Vasilenko, D.A., Zadorozhny, A.G., Kostyuk, P.G.: Synaptic processes in spinal neurons monosynaptically activated from the pyramidal tract. Bull. Exp. Biol. Med. USSR 64, 20–25 (1967)
Willis, W.D., Tate, G.W., Ashworth, R.D., Willis, J.C.: Monosynaptic excitation of motoneurons of individual forelimb muscles. J. Neurophysiol. 29, 410–424 (1966)
Author information
Authors and Affiliations
Additional information
Supported by the Deutsche Forschungsgemeinschaft
IBRO/UNESCO Fellow
Rights and permissions
About this article
Cite this article
Illert, M., Lundberg, A. & Tanaka, R. Integration in descending motor pathways controlling the forelimb in the cat. 1. Pyramidal effects on motoneurones. Exp Brain Res 26, 509–519 (1976). https://doi.org/10.1007/BF00238824
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00238824