Effects of GABAB receptor expression level on cognitive impairment and Arc/Arg3.1 expression in induced epileptic rats model

Abstract

To investigate the effects of GABAB receptor on cognitive impairment by using pilocarpine induced kindled rats model and also to check early gene (Arc/Arg3.1) expression. Pilocarpine induced kindled rats were divided into four groups (Group normal, Baclofen, CGP and Kindled) randomly, and every group included 20 rats.We checked their cognitive impairment by using passive avoidance test and water maze test.The expression of GABAB receptor (GB1, GB2) and Arc/Arg3.1 was tested by immunohistochemical staining, RT-PCR and Western blot. Passive avoidance test showed four Group rats shuttle times were 6.8±0.6, 1.2±0.2, 5.4±0.5, 3.6±0.3, incubation period were 26.1±3.9, 152.2±12.9, 65.8±7.0, 91.2±9.1, and water maze test had the same trend, with values in epilepsy groups significantly lower than the normal group of rats, which meant cognitive dysfunction.The above results also showed Baclofen further inhibited the learning and memory ability of the rats and CGP35348 promoted the learning and memory ability.The results of the Arc/Arg3.1 and GB1, GB2 level detection showed that epilepsy groups had significantly higher expression levels of Arc/Arg3.1 and GB1, GB2 than the normal group.Comparison among epilepsy groups showed that Baclofen group expressed lower levels of Arc/Arg3.1 and expressed higher levels of GB1, GB2, however CGP35348 group expressed higher levels of Arc/Arg3.1 and expressed lower levels of GB1, GB2. GABAB receptor can affect the ability of spatial learning and memory of epileptic rats by regulating Arc/Arg3.1.