The role of proprioceptive feedback in locomotion

Principal collaborator: Anthony Taylor, Professor (Emeritus) of Neurophysiology, Imperial College.

Our principal research interest is the role played by muscle spindles in locomotion.

The complex sequences of muscle activation during locomotion are produced by central pattern generators lying in the spinal cord.  However, animals and man lacking sensory feedback from muscle and joints (proprioception) and the skin are unable to walk.  By far the most complex of peripheral sense organs providing the feedback essential for locomotion, is the muscle spindle.  It is unique in that its sensitivity (to muscle length changes) is controlled by the central nervous system through a gamma (fusimotor) motor innervation. 




In the recent past we have established:

• Techniques for identifying the contributions of the three different types of intrafusal muscle fibre that adjust sensitivity of the spindle sensory endings.
• The patterns of extensor and flexor spindle afferent discharges during locomotion.
• The discovery of a temporal template of intended movement coded in spindle afferent discharges.
• The discharge patterns of static and dynamic gamma motoneurones during locomotion.

Our on-going aim is to establish the precise function of the sensory feedback from this complex proprioceptor in the control of locomotion.

Publications:

Taylor, A., Ellaway, P.H., & Durbaba, R. (1999) Why are there three types of intrafusal muscle fibers? Progress in Brain Research 123, 121-131.

Taylor, A., Durbaba, R., Ellaway, P.H. & Rawlinson, S.R. (2000) Patterns of fusimotor activity during locomotion in the decerebrate cat deduced from recordings from hindlimb muscle spindles. Journal of Physiology. 522, 515-532.
*Paper selected for a Perspective article in the Journal of Physiology.

Taylor A., Ellaway P.H., Durbaba R. & Rawlinson, S.R. (2000) Distinctive patterns of static and dynamic gamma motor activity during locomotion in the decerebrate cat. Journal of Physiology 529, 825-836.

Durbaba R., Taylor A., Ellaway P.H. & Rawlinson, S.R. (2001) Modulation of primary afferent discharge by dynamic and static gamma motor axons in cat muscle spindles in relation to the intrafusal fibre types activated. Journal of Physiology 532, 563-574.

Ellaway P.H., Taylor A., Durbaba R. & Rawlinson, S.R. (2002) Role of the fusimotor system in locomotion. Advances in Experimental Medicine and Biology 508, 335-342.

Durbaba, R., Taylor, A., Rawlinson S.R. &  Ellaway P.H. (2003) Static fusimotor action during locomotion in the decerebrated cat revealed by cross-correlation of spindle afferent activity. Experimental Physiology 88.2, 285-296.

Durbaba, R., Taylor, A., Ellaway P.H. & Rawlinson S.R. (2003) The influence of bag and chain intrafusal muscle fibers on secondary spindle afferents in the cat. Journal of Physiology 550, 263-278.

Ellaway P.H., Prochazka A., Chan M. & Gauthier, M.J. (2004) The sense of movement elicited by transcranial magnetic stimulation in humans is due to sensory feedback. Journal of Physiology 556.2, 651-660.