J Korean Epilepsy Soc.  2001 Dec;5(2):124-130.

The Changes of Glutamate Receptor in Kindled Rats : Metabotropic Glutamate Receptor

• Jung DS
• Kim HK
• Sohn WS

Abstract

PURPOSE: Kindling refers to a process whereby repeated applications of an initially subconvulsive electrical or chemical stimulus to animals lead to persistent epileptogenic in generalized seizures. Metabotropic glutamate receptors (mGluRs) have been shown to be involved in many brain functions. Widespread distribution of the mGluRs suggests glutamate may be the primary modulator of G-protein coupled signal transduction in the central nervous system. To investigate the role of mGluRs in kindling, we studied the changes of mRNA gene expressions of mGluR1 and 5 on the hippocampus, amygdala, and basal ganglia in PTZ-induced kindled rats.
METHODS
Male Wistar rats (n=6-4) were kindled by repeated administration, 5 times a week, by a subconvulsant dose of PTZ (35 mg/kg). After completion of kindling, the brains were analysed for mRNA gene expression of mGluR1 and 5 using reverse transcripted polymerase chain reaction (RT-PCR).
RESULTS
The kindling score was significantly increased after 8 injections and the definitive kindling score (more than 4 point) was obtained after 10 injections. mRNA gene expressions of mGluR1 in hippocampus, amygdala, and basal ganglia were increased by 180.1+/-4.4%, 130.2+/-6.1%, 148.6+/-1.4% compared to controls (p<0.05), but those of mGluR5 were not significantly increased.
CONCLUSIONS
Although the mRNA gene expression of mGluR5 did not show any marked changes in kindled rat brain, that of mGluR1 showed significant increase in hippocampus and amygdala. From these results, high density of mGluR1 may suggests glutamatergic systems plays a role in PTZ-induced kindling. But our results would not exclude the possibility that changes of mRNA gene expressions of mGluR1 and 5 are due to repeated seizure activity alone.

Keyword

Chemical kindling; Metabotropic glutamate receptor; Gene expression

MeSH Terms

Amygdala
Animals
Basal Ganglia
Brain
Central Nervous System
Gene Expression
Glutamic Acid*
GTP-Binding Proteins
Hippocampus
Humans
Male
Polymerase Chain Reaction
Rats*
Rats, Wistar
Receptors, Glutamate*
Receptors, Metabotropic Glutamate*
RNA, Messenger
Seizures
Signal Transduction
GTP-Binding Proteins
Glutamic Acid
RNA, Messenger
Receptors, Glutamate
Receptors, Metabotropic Glutamate