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Experimental Brain Research

, Volume 86, Issue 2, pp 293–302 | Cite as

Static firing rates of premotor and primary motor cortical neurons associated with torque and joint position

  • W. Werner
  • E. Bauswein
  • C. Fromm
Article

Summary

Single cell activity was studied in the postarcuate premotor area (PMA) and primary motor cortex (MI) of two monkeys performing a load-bearing task with the contralateral hand. Steady-state discharge rates were examined in relation to positional maintenance of the wrist which was held in one of three given positions against graded torques directed towards flexion or extension. Significant and monotonic relationships between tonic firing rate and static torque were found in 41% of 477 MI cells and in only 26% of 470 units studied in PMA. However, for specific cell groups in the PMA the proportion of load-related neurons reached that of the MI samples; this was true for pyramidal tract neurons (PTNs) and for ‘non-PTNs’ if recorded in their vicinity. The most interesting difference pertains to the range of load over which cells in both areas modulated activity. MI neurons showed steepest change of firing rates over a limited range of small torques around zero external load; the population average displayed a sigmoidal relationship. Proportionally more PMA neurons increased their activity over the entire range of torques examined or showed the highest increase with stronger torques; the population average best fitted a quadratic function. The mean firing ratetorque slope of the PMA population was significantly smaller than that of MI. Many cells in either area were related to both torque and joint position and displayed correlates of length-tension properties of muscle. Change of position sensitivity with torque was found to parallel the rate-torque characteristics in individual neurons. Mean position sensitivity of PMA neurons increased with increasing torques in the ‘preferred’ direction. In contrast, greatest position sensitivity of the MI population occurred over the range of low torques, which means a clear quantitative dissociation from the muscular activities. The results suggest differential roles of MI and PMA in the control of ‘fine’ versus ‘gross’ muscular forces. Undoubtedly, some PMA cell elements (possibly certain output neurons) are involved in aspects of postural control of EMG adjustment to load and joint position.

Key words

Premotor area Motor cortex Torque relation Single unit recording Monkey 

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References

  1. Bauswein E, Fromm C, Preuß A (1989) Corticostriatal cells in comparison with pyramidal tract neurons: contrasting properties in the behaving monkey. Brain Res 493: 198–203Google Scholar
  2. Bauswein E, Fromm C, Werner W, Ziemann U (1991) Phasic and tonic responses of premotor and primary motor cortex neurons to torque changes. Exp Brain Res 86: 303–310Google Scholar
  3. Bevington PR (1969) Data reduction and error analysis for the physical sciences. McGraw-Hill, New York San Francisco Toronto London SydneyGoogle Scholar
  4. Brinkman C, Porter R (1983) Supplementary motor area and premotor area of monkey cerebral cortex: functional organization and activities of single neurons during performance of a learned movement. In: Desmedt JE (eds) Advances in neurology, Vol. 39. Motor control mechanisms in health and disease. Raven, New York, pp 392–420Google Scholar
  5. Cheney PD, Fetz EE (1980) Functional classes of primate corticomotoneuronal cells and their relation to active force. J Neurophysiol 44: 773–791Google Scholar
  6. Evarts EV (1969) Activity of pyramidal tract neurons during postural fixation. J Neurophysiol 32: 375–385Google Scholar
  7. Evarts EV, Fromm C, Kröller J, Jennings VA (1983) Motor cortex control of finely graded forces. J Neurophysiol 49: 1199–1215Google Scholar
  8. Freund HJ, Hummelscheim H (1985) Lesions of premotor cortex in man. Brain 108: 697–733PubMedGoogle Scholar
  9. Fromm C (1983a) Changes in steady state activity in motor cortex consistent with the length-tension relation of muscle. Pflügers Arch 398: 318–323Google Scholar
  10. Fromm C (1983b) Contrasting properties of pyramidal tract neurons located in the pre-central or postcentral areas and of corticorubral neurons in the behaving monkey. In: Desmedt JE (eds) Advances in neurology, Vol 39. Motor control mechanisms in health and disease. Raven, New York, pp 329–345Google Scholar
  11. Georgopoulos AP, Caminiti R, Kalaska JF (1984) Static spatial effects in motor cortex and area 5: quantitative relations in a twodimensional space. Exp Brain Res 54: 446–454Google Scholar
  12. Godschalk M, Lemon RN, Kuypers HGJM, Ronday HK (1984)Cortical afferents and efferents of monkey postarcuate area: an anatomical and elctrophysiological study. Exp Brain Res 56: 410–424Google Scholar
  13. Hepp-Reymond MC, Wyss UR, Anner R (1978) Neuronal coding of static force in primate motor cortex. J Physiol Paris 74: 287–291Google Scholar
  14. Hoffman DS, Luschei ES (1980) Responses of monkey precentral cortical cells during a controlled jaw bite task. J Neurophysiol 44: 333–348Google Scholar
  15. Humphrey DR, Reed DJ (1983) Separate cortical systems for control of joint movement and joint stiffness: reciprocal activation and coactivation of antagonist muscles. In: Desmedt JE (eds) Advances in neurology, Vol 39. Motor control mechanisms in health disease. Raven, New York, pp. 347–372Google Scholar
  16. Jennings VA, Lamour Y, Solis H, Fromm C (1983) Somatosensory cortex activity related to position and force. J Neurophysiol 49: 1216–1229Google Scholar
  17. Kalaska JF, Cohen DAD, Hyde ML, Prud'homme M (1989) A comparison of movement direction-related versus load direction-related activity in primate motor cortex, using a two-dimensional reaching task. J Neurosci 9: 2080–2012Google Scholar
  18. Kurata K, Tanji J (1986) Premotor cortex neurons in macaques: activity before distal and proximal forelimb movements. J Neuro-sci 6: 403–411Google Scholar
  19. Kuypers HGJM, Brinkman J (1970) Precentral projections to different parts of the spinal intermediate zone in the rhesus monkey. Brain Res 24: 29–48Google Scholar
  20. Kuypers HGJM, Lawrence DG (1967) Cortical projections to the red nucleus and the brain stem in the rhesus monkey. Brain Res 4: 151–188CrossRefPubMedGoogle Scholar
  21. Lawrence DG, Kuypers HGJM (1968) The functional organization of the motor system in the monkey. II. The effects of lesions of the descending brain-stem pathways. Brain 91: 15–36PubMedGoogle Scholar
  22. Martino AM, Strick PL (1987) Corticospinal projections originate from the arcuate premotors areas. Brain Res 404: 307–312Google Scholar
  23. Muakkassa KF, Strick PL (1979) Frontal lobe inputs to primate motor cortex: evidence for four somatotopically organized ‘premotor ’ areas. Brain Res 177: 176–182Google Scholar
  24. Pandya DN, Vignolo LA (1971) Intra-and interhemispheric projections of the precentral, premotor, and arcuate areas in the rhesus monkey. Brain Res 26: 217–233Google Scholar
  25. Rizzolatti G, Gentilucci M, Fogassi L, Luppino G, Matelli M, Ponzoni-Maggi S (1987) Neurons related to goal-directed motor acts in inferior area 6 of the macaque monkey Exp Brain Res 67: 220–224Google Scholar
  26. Sessle BJ, Wiesendanger M (1982) Structural and funtional definition of the motor cortex in the monkey (Macaca fascicularis). J Physiol Lond 323: 245–265Google Scholar
  27. Tanji J, Okano K, Sato KC (1988) Neuronal activity in cortical motor areas related to ipsilateral, contralateral, and bilateral digit movements of the monkey. J Neurophysiol 60: 325–343PubMedGoogle Scholar
  28. Thach WT (1978) Correlation of neural discharge with pattern and force muscular activity, joint position and direction of intended next movement in motor cortex and cerebellum. J Neurophysiol 41: 654–676Google Scholar
  29. Weinrich M, Wise SP (1982) The premotor cortex of the monkey. J Neurosci 2: 1329–1345PubMedGoogle Scholar
  30. Weinrich M, Wise SP, Mauritz KH (1984) A neurophysiological study of the premotor cortex in the rhesus monkey. Brain 107: 385–414PubMedGoogle Scholar
  31. Wise SP (1985) The primate premotor cortex: past, present, and preparatory. Ann Rev Neurosci 8: 1–19Google Scholar
  32. Wise SP, Weinrich M, Mauritz KH (1986) Movement-related activity in the premotor cortex of rhesus macaques. Progr Brain Res 64: 117–131Google Scholar

Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • W. Werner
    • 1
  • E. Bauswein
    • 1
  • C. Fromm
    • 1
  1. 1.Abteilung Neurobiologie, Max-Planck-Institut für biophysikalische ChemieGöttingenFederal Republic of Germany

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