Peripheral inflamation-induced increase of AMPA-mediated currents and Ca2+ transients in the presence of cyclothiazide in the rat substantia gelatinosa neurons.

Abstract

This study employing a rodent model of acute pain investigated the influence of carrageenan-induced inflammation on the ability of S-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor activation to induce membrane currents and rises in cytosolic free calcium concentration ([Ca2+]i) in the rat substantia gelatinosa (SG) neurons using simultaneous whole-cell patch-clamp recording and fura-2 calcium imaging in spinal cord slices of L4-L5 segments. The novel finding of this study is that carrageenan-induced inflammation, in the presence of cyclothiazide, an inhibitor of AMPA receptor desensitization, produces a sustained facilitation of the AMPA-mediated membrane current and rises in [Ca2+]i in both the soma and proximal dendrites of SG neurons recorded on the injected side 3 h after the induction of inflammation. These results suggest that in carrageenan-inflamed rats AMPA receptors undergo some alterations that influence AMPA receptors desensitization and/or sensitivity to cyclothiazide.

• Authors: N Voitenko, G Gerber, D Youn, M Randic
• Journal: Cell calcium (Cell Calcium) Vol. 35 Issue 5 Pg. 461-9 (May 2004) ISSN: 0143-4160 [Print] Netherlands
• PMID: 15003855 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Antihypertensive Agents
• Benzothiadiazines
• Excitatory Amino Acid Agonists
• Receptors, AMPA
• alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
• Carrageenan
• cyclothiazide
• Calcium

Topics

• Animals
• Antihypertensive Agents (pharmacology)
• Benzothiadiazines (pharmacology)
• Calcium (metabolism)
• Calcium Signaling (drug effects, physiology)
• Carrageenan (toxicity)
• Excitatory Amino Acid Agonists (pharmacology)
• Female
• In Vitro Techniques
• Inflammation (chemically induced, metabolism)
• Male
• Membrane Potentials
• Neurons (physiology)
• Patch-Clamp Techniques
• Rats
• Rats, Sprague-Dawley
• Receptors, AMPA (agonists, antagonists & inhibitors, metabolism)
• Substantia Gelatinosa (physiology)
• alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (pharmacology)