QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, September 8, 2004, 24(36):7804-7813; doi:10.1523/JNEUROSCI.1941-04.2004

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (22) Citing Articles via Google Scholar Google Scholar Articles by Edgley, S. A. Articles by Hammar, I. Search for Related Content PubMed PubMed Citation Articles by Edgley, S. A. Articles by Hammar, I.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Ipsilateral Actions of Feline Corticospinal Tract Neurons on Limb Motoneurons

S. A. Edgley,² E. Jankowska,¹ and I. Hammar¹

¹Department of Physiology, Göteborg University, 405 30 Göteborg, Sweden, and ²Department of Anatomy, Cambridge University CB2 3DY, United Kingdom

Contralateral pyramidal tract (PT) neurons arising in the primary motor cortex are the major route through which volitional limb movements are controlled. However, the contralateral hemiparesis that follows PT neuron injury on one side may be counteracted by ipsilateral of actions of PT neurons from the undamaged side. To investigate the spinal relays through which PT neurons may influence ipsilateral motoneurons, we analyzed the synaptic actions evoked by stimulation of the ipsilateral pyramid on hindlimb motoneurons after transecting the descending fibers of the contralateral PT at a low thoracic level. The results show that ipsilateral PT neurons can affect limb motoneurons trisynaptically by activating contralaterally descending reticulospinal neurons, which in turn activate spinal commissural interneurons that project back across to motoneurons ipsilateral to the stimulated pyramidal tract. Stimulation of the pyramids alone did not evoke synaptic actions in motoneurons but potently facilitated disynaptic EPSPs and IPSPs evoked by stimulation of reticulospinal tract fibers in the medial longitudinal fascicle. In parallel with this double-crossed pathway, corticospinal neurons could also evoke ipsilateral actions via ipsilateral descending reticulospinal tract fibers, acting through ipsilaterally located spinal interneurons. Because the actions mediated by commissural interneurons were found to be stronger than those of ipsilateral premotor interneurons, the study leads to the conclusion that ipsilateral actions of corticospinal neurons via commissural interneurons may provide a better opportunity for recovery of function in hemiparesis produced by corticospinal tract injury.

Key words: pyramidal tract; motor system; spinal cord; reticular formation; commissural interneurons; cat

---

Received May 19, 2004; revised June 25, 2004; accepted July 13, 2004.

This article has been cited by other articles:

				M. Brus-Ramer, J. B. Carmel, and J. H. Martin Motor Cortex Bilateral Motor Representation Depends on Subcortical and Interhemispheric Interactions J. Neurosci., May 13, 2009; 29(19): 6196 - 6206. [Abstract] [Full Text] [PDF]

				C. N. Riddle, S. A. Edgley, and S. N. Baker Direct and Indirect Connections with Upper Limb Motoneurons from the Primate Reticulospinal Tract J. Neurosci., April 15, 2009; 29(15): 4993 - 4999. [Abstract] [Full Text] [PDF]

				S. Chakrabarty, K. M. Friel, and J. H. Martin Activity-Dependent Plasticity Improves M1 Motor Representation and Corticospinal Tract Connectivity J Neurophysiol, March 1, 2009; 101(3): 1283 - 1293. [Abstract] [Full Text] [PDF]

				K. Stecina, U. Slawinska, and E. Jankowska Ipsilateral actions from the feline red nucleus on hindlimb motoneurones J. Physiol., December 15, 2008; 586(24): 5865 - 5884. [Abstract] [Full Text] [PDF]

				I. Salimi, K. M. Friel, and J. H. Martin Pyramidal Tract Stimulation Restores Normal Corticospinal Tract Connections and Visuomotor Skill after Early Postnatal Motor Cortex Activity Blockade J. Neurosci., July 16, 2008; 28(29): 7426 - 7434. [Abstract] [Full Text] [PDF]

				K. Stecina, E. Jankowska, A. Cabaj, L.-G. Pettersson, B. A. Bannatyne, and D. J. Maxwell Premotor interneurones contributing to actions of feline pyramidal tract neurones on ipsilateral hindlimb motoneurones J. Physiol., January 15, 2008; 586(2): 557 - 574. [Abstract] [Full Text] [PDF]

				K. A. Quinlan and O. Kiehn Segmental, Synaptic Actions of Commissural Interneurons in the Mouse Spinal Cord J. Neurosci., June 13, 2007; 27(24): 6521 - 6530. [Abstract] [Full Text] [PDF]

				K. Stecina and E. Jankowska Uncrossed actions of feline corticospinal tract neurones on hindlimb motoneurones evoked via ipsilaterally descending pathways J. Physiol., April 1, 2007; 580(1): 119 - 132. [Abstract] [Full Text] [PDF]

				E. Jankowska and K. Stecina Uncrossed actions of feline corticospinal tract neurones on lumbar interneurones evoked via ipsilaterally descending pathways J. Physiol., April 1, 2007; 580(1): 133 - 147. [Abstract] [Full Text] [PDF]

				E. Jankowska, K. Stecina, A. Cabaj, L.-G. Pettersson, and S. A. Edgley Neuronal relays in double crossed pathways between feline motor cortex and ipsilateral hindlimb motoneurones J. Physiol., September 1, 2006; 575(2): 527 - 541. [Abstract] [Full Text] [PDF]

				A. Cabaj, K. Stecina, and E. Jankowska Same Spinal Interneurons Mediate Reflex Actions of Group Ib and Group II Afferents and Crossed Reticulospinal Actions J Neurophysiol, June 1, 2006; 95(6): 3911 - 3922. [Abstract] [Full Text] [PDF]

				B. A. Bannatyne, S. A. Edgley, I. Hammar, E. Jankowska, and D. J. Maxwell Differential projections of excitatory and inhibitory dorsal horn interneurons relaying information from group II muscle afferents in the cat spinal cord. J. Neurosci., March 15, 2006; 26(11): 2871 - 2880. [Abstract] [Full Text] [PDF]

				E. Jankowska and S. A. Edgley How Can Corticospinal Tract Neurons Contribute to Ipsilateral Movements? A Question With Implications for Recovery of Motor Functions Neuroscientist, February 1, 2006; 12(1): 67 - 79. [Abstract] [PDF]

				E Jankowska, P Krutki, and K Matsuyama Relative contribution of Ia inhibitory interneurones to inhibition of feline contralateral motoneurones evoked via commissural interneurones J. Physiol., October 15, 2005; 568(2): 617 - 628. [Abstract] [Full Text] [PDF]

				G. Courtine, R. R. Roy, J. Raven, J. Hodgson, H. Mckay, H. Yang, H. Zhong, M. H. Tuszynski, and V. R. Edgerton Performance of locomotion and foot grasping following a unilateral thoracic corticospinal tract lesion in monkeys (Macaca mulatta) Brain, October 1, 2005; 128(10): 2338 - 2358. [Abstract] [Full Text] [PDF]

				E. Jankowska, A. Cabaj, and L.-G. Pettersson How to Enhance Ipsilateral Actions of Pyramidal Tract Neurons J. Neurosci., August 10, 2005; 25(32): 7401 - 7405. [Abstract] [Full Text] [PDF]

				M. K. Floeter, P. Zhai, R. Saigal, Y. Kim, and J. Statland Motor Neuron Firing Dysfunction in Spastic Patients With Primary Lateral Sclerosis J Neurophysiol, August 1, 2005; 94(2): 919 - 927. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help