Changes of glucocorticoid receptor mRNA expression in basolateral amygdale-kindled rats

Glucocorticoid receptor (GR) is believed to be a major factor in brain maturation and in modulation of a series of brain activity. Hippocampal neurons are abundant in glucocorticoid receptor, and there is significant change in GR expression under certain pathological state. Epilepsy is a special pathological state of the central nervous system. This study aimed to explore the role of GR in epilepsy by observing the change and functions of GR in hippocampus with a basolateral amygdale-electrical kindled rat epilepsy model.

Firstly, we established the basolateral amygdale-electrical kindled rat epilepsy model. Then GR mRNA expression in the hippocampus was assayed by semi-quantitative reverse transcription-PCR in this experiment. In addition, the processes of epileptic seizures were observed and electroencephalograms were recorded. One-way analysis of variance (ANOVA) was employed for comparing means of multiple groups, followed Fisher's least significant difference (LSD) for paired comparison.

The rats were successfully kindled after an average of (13.50 ± 3.99) times electrical stimulation, in which it was showed that GR mRNA expression reduced obviously as compared with the control group and the sham groups (P < 0.001). The down-regulation of GR mRNA expression was abated or reversed by some anti-epilepsy drugs (P < 0.001 compared with the epilepsy group), accompanied by attenuation of seizures and improvement of electroencephalograms.

Down-regulation of hippocampal GR mRNA expression may be related to the kindling. Anti-epilepsy drugs exposure can retard this change.