|
|
||||||||
1Department of Physiology and 2Department of Pharmacology, Zhongshan Medical School of Sun Yat-sen University, Guangzhou 510089, Peoples Republic of China
Submitted 31 July 2003; accepted in final form 13 October 2003
Long-term potentiation (LTP) of C-fiber-evoked field potentials in spinal dorsal horn may be relevant to hyperalgesia, an increased response to noxious stimulation. The mechanism underlying this form of synaptic plasticity is, however, still unclear. Considerable evidence has shown that calcium/calmodulin-dependent protein kinase II (CaMKII), protein kinase A (PKA), and protein kinase C (PKC) are important for LTP in hippocampus. In this study, the roles of these three protein kinases in the induction and maintenance of LTP of C-fiber-evoked field potentials were evaluated by application of specific inhibitors of CaMKII (KN-93 and AIP), PKA (Rp-CPT-cAMPS), and PKC (chelerythrine and Gö 6983) at the recording segments before and after LTP induction in urethane-anesthetized Sprague-Dawley rats. We found both KN-93 and AIP, when applied at 30 min prior to tetanic stimulation, completely blocked LTP induction. At 30 min after LTP induction, KN-93 and AIP reversed LTP completely, and at 60 min after LTP induction, they depressed spinal LTP in most rats tested. Three hours after LTP induction, however, KN-93 or AIP did not affect the spinal LTP. Rp-CPT-cAMPS, chelerythrine, and Gö 6983 blocked the spinal LTP when applied at 30 min before tetanic stimulation and reversed LTP completely at 15 min after LTP induction. In contrast, at 30 min after LTP induction, the drugs never affected the spinal LTP. These results suggest that activation of CaMKII, PKA, and PKC may be crucial for the induction and the early-phase but not for the late-phase maintenance of the spinal LTP.
This article has been cited by other articles:
![]() |
M. Larsson and J. Broman Translocation of GluR1-Containing AMPA Receptors to a Spinal Nociceptive Synapse during Acute Noxious Stimulation J. Neurosci., July 9, 2008; 28(28): 7084 - 7090. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. L. Jones, A. C. Lustig, and L. S. Sorkin Secondary Hyperalgesia in the Postoperative Pain Model Is Dependent on Spinal Calcium/Calmodulin-Dependent Protein Kinase II{alpha} Activation Anesth. Analg., December 1, 2007; 105(6): 1650 - 1656. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. Grau, E. D. Crown, A. R. Ferguson, S. N. Washburn, M. A. Hook, and R. C. Miranda Instrumental learning within the spinal cord: underlying mechanisms and implications for recovery after injury. Behav Cogn Neurosci Rev, December 1, 2006; 5(4): 191 - 239. [Abstract] [PDF] |
||||
![]() |
T. Klein, W. Magerl, and R.-D. Treede Perceptual Correlate of Nociceptive Long-Term Potentiation (LTP) in Humans Shares the Time Course of Early-LTP J Neurophysiol, December 1, 2006; 96(6): 3551 - 3555. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Larsson and J. Broman Pathway-specific bidirectional regulation of Ca2+/calmodulin-dependent protein kinase II at spinal nociceptive synapses after acute noxious stimulation. J. Neurosci., April 19, 2006; 26(16): 4198 - 4205. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. R. Reeves, E. S. Carter, S. Z. Guo, and D. Gozal Calcium/calmodulin-dependent kinase II mediates critical components of the hypoxic ventilatory response within the nucleus of the solitary tract in adult rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2005; 289(3): R871 - R876. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-W. Yang, L.-J. Zhou, N.-W. Hu, W.-J. Xin, and X.-G. Liu Activation of Spinal D1/D5 Receptors Induces Late-Phase LTP of C-Fiber-Evoked Field Potentials in Rat Spinal Dorsal Horn J Neurophysiol, August 1, 2005; 94(2): 961 - 967. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |