J Korean Child Neurol Soc.  2006 May;14(1):16-23.

High K-induced Epileptiform Activity under GABA Antagonist and Carbamazepine in the Rat Visual Cortex

• Choi BJ

Abstract

PURPOSE: The goal of this study was to investigate the effect of increase of K on the excitability of the visual cortex under GABA antagonist, carbamazepine(CBZP), 6-cyano-7-nitroquinoxaline-dione disodium(CNQX) and D-(-)-2-amino-5-phosphonopentanoic acid(D-AP5) on the increase of K-induced epileptiform activity.
METHODS
The visual cortex slices were obtained from Sprague-Dawley rats. Extracellular recordings were performed to observe the induction of epileptiform discharges perfused by artificial CSF(ACSF) with an increase of K and the effect of 0.5 and 1 mM CBZP, 10 micrometer CNQX and 50 micrometer D-AP5 on the increase of K-induced epileptiform activity.
RESULTS
Spontaneous epileptiform activities were increased by ACSF with 10 mM K under bicuculline compared to 4 mM K. CBZP blocked and 10 micrometer CNQX and 50 micrometer D-AP5 decreased the 10 mM K-induced spontaneous epileptiform activity.
CONCLUSION
An increase of K augmented spontaneous epileptiform activity. This experimental model increased the excitability of the brain, which may be influenced by GABA. CBZP blocked the increase of K-induced epileptiform activity, which showed the increase of excitability. An increase of K-induced epileptiform activity was decreased by CNQX and D-AP5, which may show the attenuation of voltage-dependent low magnesium effect and decrease the excitability in terms of synapse induction.

Keyword

K; Carbamazepine

MeSH Terms

6-Cyano-7-nitroquinoxaline-2,3-dione
Animals
Bicuculline
Brain
Carbamazepine*
GABA Antagonists*
gamma-Aminobutyric Acid*
Magnesium
Models, Theoretical
Rats*
Rats, Sprague-Dawley
Synapses
Visual Cortex*
6-Cyano-7-nitroquinoxaline-2,3-dione
Bicuculline
Carbamazepine
GABA Antagonists
Magnesium
gamma-Aminobutyric Acid