Behavioral deficit and decreased GABA receptor functional regulation in the hippocampus of epileptic rats: effect of Bacopa monnieri.

In the present study, alterations of the General GABA and GABA(A) receptors in the hippocampus of pilocarpine-induced temporal lobe epileptic rats and the therapeutic application of Bacopa monnieri and its active component Bacoside-A were investigated. Bacopa monnieri (Linn.) is a herbaceous plant belonging to the family Scrophulariaceae. Hippocampus is the major region of the brain belonging to the limbic system and plays an important role in epileptogenesis, memory and learning. Scatchard analysis of [³H]GABA and [³H]bicuculline in the hippocampus of the epileptic rat showed significant decrease in B(max) (P < 0.001) compared to control. Real Time PCR amplification of GABA(A) receptor sub-units such as GABA(Aά₁), GABA(Aά₅) GABA(Aδ), and GAD were down regulated (P < 0.001) in the hippocampus of the epileptic rats compared to control. GABA(Aγ) subunit was up regulated. Epileptic rats have deficit in the radial arm and Y maze performance. Bacopa monnieri and Bacoside-A treatment reverses all these changes near to control. Our results suggest that decreased GABA receptors in the hippocampus have an important role in epilepsy associated behavioral deficit, Bacopa monnieri and Bacoside-A have clinical significance in the management of epilepsy.