This report was presented at a symposium on Neural circuits in movement control, which took place Trolleholm Castle (Lund), Sweden on 27–28 May, 2011.
Interactions between spinal interneurons and ventral spinocerebellar tract neurons
Article first published online: 19 FEB 2013
© 2013 The Authors. The Journal of Physiology © 2013 The Physiological Society
The Journal of Physiology
Volume 591, Issue 22, pages 5445–5451, November 2013
How to Cite
Jankowska, E. and Hammar, I. (2013), Interactions between spinal interneurons and ventral spinocerebellar tract neurons. The Journal of Physiology, 591: 5445–5451. doi: 10.1113/jphysiol.2012.248740
- Issue published online: 14 NOV 2013
- Article first published online: 19 FEB 2013
- Accepted manuscript online: 18 JAN 2013 10:00AM EST
- (Received 19 November 2012; accepted after revision 10 January 2013; first published online 21 January 2013)
Abstract Recent evidence indicates that ventral spinocerebellar tract (VSCT) neurons do not merely receive information provided by spinal interneurons but may also modulate the activity of these interneurons. Hence, interactions between them may be mutual. However, while it is well established that spinal interneurons may provide both excitatory and inhibitory input to ascending tract neurons, the functional consequences of the almost exclusively inhibitory input from premotor interneurons to subpopulations of VSCT neurons were only recently addressed. These are discussed in the first part of this review. The second part of the review summarizes evidence that some VSCT neurons may operate both as projection neurons and as spinal interneurons and play a role in spinal circuitry. It outlines the evidence that initial axon collaterals of VSCT neurons target premotor inhibitory interneurons in disynaptic reflex pathways from tendon organs and muscle spindles (group Ia, Ib and/or II muscle afferents) to motoneurons. By activating these interneurons VSCT neurons may evoke disynaptic IPSPs in motoneurons and thus facilitate inhibitory actions of contralateral muscle afferents on motoneurons. In this way they may contribute to the coordination between neuronal networks on both sides of the spinal cord in advance of modulatory actions evoked via the cerebellar control systems.