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Neurons in the pontomedullary reticular formation signal posture and movement both as an integrated behavior and independently

Journal Article


Abstract


  • We have previously suggested that the discharge characteristics of some neurons in the pontomedullary reticular formation (PMRF) are contingent on the simultaneous requirement for activity in both ipsilateral flexor muscles and contralateral extensors. To test this hypothesis we trained cats to stand on four force platforms and to perform a task in which they were required to reach forward with one forelimb or the other and depress a lever. As such the task required the cat to make a flexion movement followed by an extension in the reaching limb while maintaining postural support by increasing extensor muscle tonus in the supporting limbs. We recorded the activity of 131 neurons from the PMRF of three cats during left, ipsilateral reach. Of these, 86/131 (66%) showed a change in discharge frequency prior to the onset of activity in one of the prime flexor muscles and 43/86 (50%) showed a bimodal pattern of discharge in which activity decreased during the lever press. Among the remaining cells, 28/86 (33%) showed maintained activity throughout the reach and the lever press. Most cells showed a broadly similar pattern of discharge during reaches with the right, contralateral limb. We suggest these results support the view that a population of neurons within the PMRF contributes to the control of movement in one forelimb and the control of posture in the other forelimb as a coordinated unit. Another population of neurons contributes to the control of postural support independently of the nature of the activity in the reaching limb.

Authors


  •   Schepens, Benedicte (external author)
  •   Stapley, Paul J.
  •   Drew, Trevor (external author)

Publication Date


  • 2008

Citation


  • Schepens, B., Stapley, P. J. & Drew, T. (2008). Neurons in the pontomedullary reticular formation signal posture and movement both as an integrated behavior and independently. Journal of Neurophysiology, 100 (4), 2235-2253.

Scopus Eid


  • 2-s2.0-57349173973

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3225

Has Global Citation Frequency


Number Of Pages


  • 18

Start Page


  • 2235

End Page


  • 2253

Volume


  • 100

Issue


  • 4

Abstract


  • We have previously suggested that the discharge characteristics of some neurons in the pontomedullary reticular formation (PMRF) are contingent on the simultaneous requirement for activity in both ipsilateral flexor muscles and contralateral extensors. To test this hypothesis we trained cats to stand on four force platforms and to perform a task in which they were required to reach forward with one forelimb or the other and depress a lever. As such the task required the cat to make a flexion movement followed by an extension in the reaching limb while maintaining postural support by increasing extensor muscle tonus in the supporting limbs. We recorded the activity of 131 neurons from the PMRF of three cats during left, ipsilateral reach. Of these, 86/131 (66%) showed a change in discharge frequency prior to the onset of activity in one of the prime flexor muscles and 43/86 (50%) showed a bimodal pattern of discharge in which activity decreased during the lever press. Among the remaining cells, 28/86 (33%) showed maintained activity throughout the reach and the lever press. Most cells showed a broadly similar pattern of discharge during reaches with the right, contralateral limb. We suggest these results support the view that a population of neurons within the PMRF contributes to the control of movement in one forelimb and the control of posture in the other forelimb as a coordinated unit. Another population of neurons contributes to the control of postural support independently of the nature of the activity in the reaching limb.

Authors


  •   Schepens, Benedicte (external author)
  •   Stapley, Paul J.
  •   Drew, Trevor (external author)

Publication Date


  • 2008

Citation


  • Schepens, B., Stapley, P. J. & Drew, T. (2008). Neurons in the pontomedullary reticular formation signal posture and movement both as an integrated behavior and independently. Journal of Neurophysiology, 100 (4), 2235-2253.

Scopus Eid


  • 2-s2.0-57349173973

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3225

Has Global Citation Frequency


Number Of Pages


  • 18

Start Page


  • 2235

End Page


  • 2253

Volume


  • 100

Issue


  • 4