HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 90/2/683    most recent 00152.2003v1 Alert me when this article is cited 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 (9) Citing Articles via Google Scholar Google Scholar Articles by Meng, Z. Articles by Martin, J. H. Search for Related Content PubMed PubMed Citation Articles by Meng, Z. Articles by Martin, J. H.

Postnatal Development of Corticospinal Postsynaptic Action

¹ Center for Neurobiology and Behavior, New York City, New York 10032 ² New York State Psychiatric Institute, New York City, New York 10032

Submitted 18 February 2003; accepted in final form 31 March 2003

The corticospinal system has a delayed and prolonged postnatal development. In the cat, lesion, inactivation, or stimulation of the system influence motor output minimally when corticospinal (CS) terminals have an immature topographic pattern but produce robust effects immediately after developing the mature pattern by weeks 6–7. In this study, we directly tested if the delay in expression of cortical motor functions is due to the inability of the corticospinal synapse to activate spinal neurons. We stimulated corticospinal axons in the pyramid and recorded evoked field potentials from the surface of the cervical spinal cord and locally from within the gray matter in anesthetized cats during development and in adults. Pyramidal stimulation in animals between week 4 and maturity evoked an initial corticospinal surface volley followed by a postsynaptic field response. Depth recordings from the superficial dorsal horn to the ventral white matter showed that local pre- and postsynaptic field potentials could be recorded over the full extent of the gray matter in 4- to 5-wk animals but were restricted to the intermediate zone in older animals and adults. Dorsoventral refinement of CS field potentials parallels anatomical refinement of individual CS axon terminals shown in our earlier studies. Our present findings indicate that the developing corticospinal system could influence the excitability of virtually the entire contralateral gray matter before cortical motor functions are expressed. Given the importance of activity-dependent axon terminal refinement, this capacity for activating spinal neurons during early postnatal life could play an important role in development of CS circuit connectivity.

This article has been cited by other articles:

				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. M. Friel and J. H. Martin Bilateral Activity-Dependent Interactions in the Developing Corticospinal System J. Neurosci., October 10, 2007; 27(41): 11083 - 11090. [Abstract] [Full Text] [PDF]

				T. Kamiyama, N. Yoshioka, and M. Sakurai Synapse Elimination in the Corticospinal Projection During the Early Postnatal Period J Neurophysiol, April 1, 2006; 95(4): 2304 - 2313. [Abstract] [Full Text] [PDF]

				J. H. Martin The Corticospinal System: From Development to Motor Control Neuroscientist, April 1, 2005; 11(2): 161 - 173. [Abstract] [PDF]

				I. Salimi and J. H. Martin Rescuing Transient Corticospinal Terminations and Promoting Growth with Corticospinal Stimulation in Kittens J. Neurosci., May 26, 2004; 24(21): 4952 - 4961. [Abstract] [Full Text] [PDF]

				Z. Meng, Q. Li, and J. H. Martin The Transition from Development to Motor Control Function in the Corticospinal System J. Neurosci., January 21, 2004; 24(3): 605 - 614. [Abstract] [Full Text] [PDF]