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) 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 ISI 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 ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Zhang, X. Articles by Giesler, G. J. Search for Related Content PubMed PubMed Citation Articles by Zhang, X. Articles by Giesler, G. J., Jr

Response Characterstics of Spinothalamic Tract Neurons That Project to the Posterior Thalamus in Rats

Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota

Submitted 6 December 2004; accepted in final form 21 December 2004

A sizeable number of spinothalamic tract axons terminate in the posterior thalamus. The functional roles and precise areas of termination of these axons have been a subject of recent controversy. The goals of this study were to identify spinothalamic tract neurons (STT) within the cervical enlargement that project to this area, characterize their responses to mechanical and thermal stimulation of their receptive fields, and use microantidromic tracking methods to determine the nuclei in which their axons terminate. Forty-seven neurons were antidromically activated using low-amplitude (30 µA) current pulses in the contralateral posterior thalamus. The 51 points at which antidromic activation thresholds were lowest were surrounded by ineffective tracks indicating that the surrounded axons terminated within the posterior thalamus. The areas of termination were located primarily in the posterior triangular, medial geniculate, posterior and posterior intralaminar, and suprageniculate nuclei. Recording points were located in the superficial and deep dorsal horn. The mean antidromic conduction velocity was 6.4 m/s, a conduction velocity slower than that of other projections to the thalamus or hypothalamus in rats. Cutaneous receptive fields appeared to be smaller than those of neurons projecting to other areas of the thalamus or to the hypothalamus. Each of the examined neurons responded exclusively or preferentially to noxious stimuli. These findings indicate that the STT carries nociceptive information to several target nuclei within the posterior thalamus. We discuss the evidence that this projection provides nociceptive information that plays an important role in fear conditioning.

This article has been cited by other articles:

				S. Davidson, X. Zhang, S. G. Khasabov, D. A. Simone, and G. J. Giesler Jr. Termination Zones of Functionally Characterized Spinothalamic Tract Neurons Within the Primate Posterior Thalamus J Neurophysiol, October 1, 2008; 100(4): 2026 - 2037. [Abstract] [Full Text] [PDF]

				P. H. Smith, E. L. Bartlett, and A. Kowalkowski Cortical and Collicular Inputs to Cells in the Rat Paralaminar Thalamic Nuclei Adjacent to the Medial Geniculate Body J Neurophysiol, August 1, 2007; 98(2): 681 - 695. [Abstract] [Full Text] [PDF]

				X. Zhang, S. Davidson, and G. J. Giesler Jr Thermally identified subgroups of marginal zone neurons project to distinct regions of the ventral posterior lateral nucleus in rats. J. Neurosci., May 10, 2006; 26(19): 5215 - 5223. [Abstract] [Full Text] [PDF]