Abstract

Increased GABA (A) Receptors alpha1, gamma2, delta Subunits might be Associated with the Activation of the CREB Gene in Low Mg2+ Model of Epilepsy

Author(s): Jinpeng Yu, Zhaoyang Liu, Likun Wang, Guofeng Wu, Mali Wu

Objectives:

To observe the GABA (A) receptor subunits and the c-AMP response element binding protein (CREB) changes and their relationship in low Mg2+ model of epilepsy.

Methods:

A total of 36 embryonic rats prepared from adult female SD rats at the age of 90-100 days were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg2+ solutions to generate a low Mg2+ model of epilepsy. The low Mg2+ stimulation lasted for 9 hours, and three time points (3, 6, 9h after the neurons were exposed to the low Mg2+ solutions) were selected to observe the GABA(A) receptor and the CREB changes. The quantification of the GABA(A) receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method.

Results:

During the low Mg2+ stimulation, the GABA (A) receptors increased remarkably compared to the control after the neurons were exposed to the low Mg2+ solutions for three hours, and then it decreased gradually. A time-dependent decrease was observed during the period of observation. A significant difference was observed among the time points. The CREB decreased significantly compared to the control at 3h time point, and then it increased gradually in a time-dependent manner, and reached to a peak at 9h time point. A significant increase at 6h and 9h time point was observed as compared to the control. All the GABA (A) receptor subunit α1, γ2, δ increased at 9h time point compared to the normal control. The CREB displayed a similar result.

Conclusions:

The increase of GABA(A) receptors might be associated with the CREB expressions in cultured hippocampal neurons under low Mg2+ conditions.