Abstract
Endogenous kynurenic acid (KYNA), an excitatory amino acid receptor antagonist with antineurotoxic and anticonvulsant activity, was assessed by microdialysis in the hippocampus of kindled rats. One week after the completion of amygdala or hippocampal kindling (stage 5), the dialysate concentration of KYNA in the hippocampus of both hemispheres was 1.7 +/- 0.1-fold higher than in shams (P < 0.01). Veratridine (50 microM), applied through the probe, reduced extracellular KYNA by 28% within 1 h in controls (P < 0.05), but was ineffective in stage 5 kindled rats. At the preconvulsive stage 2, dialysate KYNA concentration and the effect of veratridine were similar to controls. The activity of KYNA's biosynthetic enzyme, kynurenine aminotransferase, did not change in the hippocampus 1 week after stage 5 seizures. These data indicate an enhanced liberation of KYNA in teh hippocampus of fully kindled animals due to an impairment of normal regulatory mechanisms. This may be of relevance for the control of hippocampal excitability during epileptogenesis.
References
May 11, 1992·Annals of the New York Academy of Sciences·R SchwarczR C Roberts
Feb 28, 1992·Brain Research·Y MinamotoO Hatase
Jul 15, 1992·The Journal of Comparative Neurology·F DuR Schwarcz
Mar 31, 1992·European Journal of Pharmacology·H Q WuR Schwarcz
Nov 1, 1991·Journal of Neurochemistry·F MoroniR Pellicciari
Aug 1, 1991·Proceedings of the National Academy of Sciences of the United States of America·O StewardE Lothman
Jul 1, 1991·Experimental Neurology·H Q WuR Schwarcz
Aug 1, 1991·Journal of Neurochemistry·E OkunoR Schwarcz
Aug 1, 1990·Trends in Pharmacological Sciences·R DingledineJ O McNamara
Oct 29, 1990·Brain Research·A HansenD I Barry
Jan 1, 1990·Journal of Neurochemistry·C Speciale, R Schwarcz
Apr 24, 1986·Neuroscience Letters·M E MonetaE Jaimovich
Jan 1, 1989·Neuroscience·J H Schneiderman, J F MacDonald
May 1, 1989·Journal of Neurochemistry·W A TurskiR Schwarcz
Apr 22, 1988·Neuroscience Letters·A VezzaniR Samanin
Jan 1, 1988·Glia·H SontheimerM Schachner
Apr 16, 1987·Nature·I Mody, U Heinemann
Sep 1, 1988·Epilepsy Research·J L ThompsonD R Feldman
Mar 1, 1972·Electroencephalography and Clinical Neurophysiology·R J Racine
Aug 10, 1984·Neuroscience Letters·A C FosterR Schwarcz
May 1, 1994·Epilepsy Research·Y Ueda, N Tsuru
Jul 1, 1994·The European Journal of Neuroscience·W KamphuisF H Lopes da Silva
Jul 1, 1994·Neuroscience·R CarpenedoF Moroni
Aug 1, 1993·Neuroscience·F DuR Schwarcz
Jul 25, 1995·European Journal of Pharmacology·H Q WuR Schwarcz
Jan 1, 1992·The European Journal of Neuroscience·Hui-Qiu WuRobert Schwarcz
Citations
Aug 24, 2011·Journal of Neural Transmission·J SzyndlerA Płaźnik
Aug 20, 2009·Journal of Molecular Neuroscience : MN·Hui-Qiu WuRobert Schwarcz
Jul 1, 1996·Brain Research·W LöscherH Lehmann
Jan 1, 1996·Brain Research Bulletin·H Q Wu, R Schwarcz
May 4, 2004·Epilepsy Research·D K HannessonM E Corcoran
Aug 6, 1998·Neuroscience·H E Scharfman, J H Goodman
Oct 19, 2011·Biomarkers in Medicine·Diane C Chugani
May 22, 2007·BMC Developmental Biology·Shan-Shan YuDi-Yun Ruan
May 10, 2005·Journal of Neuroscience Research·Wojciech RzeskiJan Albrecht
Dec 31, 2005·Metabolic Brain Disease·Jan Albrecht, Michał Wegrzynowicz
Nov 19, 1997·Journal of Neuroscience Research·P GuidettiR Schwarcz