Summary
In high spinal immobilised cats the transmission in segmental reflex pathways from cutaneous afferents and in descending propriospinal pathways from forelimb afferents to lumbar motoneurons was investigated during fictive locomotion. Synaptic responses evoked via these pathways showed basically the same dependence on the phase of the step cycle—generally EPSPs were favoured during the phase of activity of the corresponding motoneurons, while IPSPs (except for the early propriospinally mediated IPSP in FDL motoneurons) tended to increase or to occur during the phase of inactivity of the motoneurons. By this facilitation of excitatory influences and depression of inhibitory influences to motoneuron pools, the ‘locomotor generator’ may functionally support those muscles which are in their active phase, independently of the source of the stimulated afferents.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Andersson, O., Forssberg, H., Grillner, S. and Lindquist, M. (1978). Phasic gain control of the transmission in cutaneous reflex pathways to motoneurones during ‘fictive’ locomotion, Brain Res., 149, 503–507
Eccles, R. M. and Lundberg, A. (1959). Synaptic actions in motoneurones by afferents which may evoke the flexion reflex, Arch. ital. Biol., 97, 199–221
Forssberg, H. (1979). Stumbling corrective reaction: A phase-dependent compensatory reaction during locomotion, J. Neurophysiol., 42, 936–953
Forssberg, H., Grillner, S. and Rossignol, S. (1975). Phase dependent reflex reversal during walking in chronic spinal cats, Brain Res., 85, 103–107
Forssberg, H., Grillner, S. and Rossignol, S. (1977). Phasic gain control of reflexes from the dorsum of the paw during spinal locomotion, Brain Res., 132, 121–139
Grillner, S. and Zangger, P. (1974). Locomotor movements generated by the deafferented spinal cord, Acta physiol. scand., 91, 38A–39A
Grillner, S. and Zangger, P. (1979). On the central generation of locomotion in the low spinal cat, Expl Brain Res., 34, 241–261
Holmqvist, B. (1961). Crossed spinal reflex actions evoked by volleys in somatic afferents, Acta physiol. scand., 52, Suppl. 181, 1–66
Holmqvist, B. and Lundberg, A. (1961). Differential supraspinal control of synaptic actions evoked by volleys in the flexion reflex afferents in alpha motoneurones, Acta physiol. scand., 54, Suppl. 186, 1–51
Hongo, T., Jankowska, E. and Lundberg, A. (1969). The rubrospinal tract. II: Facilitation of interneuronal transmission in reflex pathways to motoneurones, Expl Brain Res., 7, 365–391
Jankowska, E., Jukes, M. G. M., Lund, S. and Lundberg, A. (1967a). The effect of DOPA on the spinal cord. 5. Reciprocal organization of pathways transmitting excitatory action to alpha motoneurones of flexors and extensors, Acta physiol. scand., 70, 369–388
Jankowska, E., Jukes, M. G. M., Lund, S. and Lundberg, A. (1967b). The effect of DOPA on the spinal cord. 6. Halfcentre organization of interneurones transmitting effects from the flexor reflex afferents, Acta physiol. scand., 70, 389–402
Lundberg, A. and Voorhoeve, P. (1962). Effects from the pyramidal tract on spinal reflex arcs, Acta physiol. scand., 56, 201–219
Miller, S., Ruit, J. B. and van der Méche, F. G. A. (1977). Reversal of sign of long spinal reflexes dependent on the phase of the step cycle in the high decerebrate cat, Brain Res., 128, 447–459
Schomburg, E. D. and Behrends, H. B. (1978a). The possibility of phase dependent monosynaptic and polysynaptic Ia excitation to homonymous motoneurones during fictive locomotion, Brain Res., 143, 533–537
Schomburg, E. D. and Behrends, H. B. (1978b). Phasic control of the transmission in the excitatory and inhibitory reflex pathways from cutaneous afferents to alpha motoneurones during fictive locomotion in cats, Neurosci. Lett., 8, 277–282
Schomburg, E. D., Meinck, H.-M. and Haustein, J. (1975). A fast propriospinal inhibitory pathway from forelimb afferents to motoneurones of hindlimb flexor digitorum longus, Neurosci. Lett., 1, 311–314
Schomburg, E. D., Meinck, H.-M., Haustein, J. and Roesler, J. (1978). Functional organization of the spinal reflex pathways from forelimb afferents to hindlimb motoneurones in the cat, Brain Res., 139, 21–33
Schomburg, E. D., Roesler, J. and Kenins, P. (1978). On the function of the fast long spinal inhibitory pathway from forelimb afferents to flexor digitorum longus motoneurones in cats and dogs, Neurosci. Lett., 7, 55–59
Schomburg, E. D., Roesler, J. and Meinck, H.-M. (1977). Phase dependent transmission in the excitatory propriospinal reflex pathway from forelimb afferents to lumbar motoneurones during fictive locomotion, Neurosci. Lett., 4, 249–252
Viala, D. and Buser, P. (1971). Modalités d’obtention de rhythmes locomoteurs chez le lapin spinal par traitements pharmacologiques (DOPA, 5-HTP, D-Amphétamine), Brain Res., 35, 151–165
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Copyright information
© 1981 The contributors
About this chapter
Cite this chapter
Schomburg, E.D., Behrends, HB., Steffens, H. (1981). Changes in segmental and propriospinal reflex pathways during spinal locomotion. In: Taylor, A., Prochazka, A. (eds) Muscle Receptors and Movement. Palgrave Macmillan, London. https://doi.org/10.1007/978-1-349-06022-1_44
Download citation
DOI: https://doi.org/10.1007/978-1-349-06022-1_44
Publisher Name: Palgrave Macmillan, London
Print ISBN: 978-1-349-06024-5
Online ISBN: 978-1-349-06022-1
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)