Expression changes of brain-derived neurotrophic factor in hippocampus of rats with post-epilepsy learning and memory deficiency / 第二军医大学学报

ABSTRACT

Objective: To study the relationship between the learning/memory ability and the expression changes of brain-derived neurotrophic factor (BDNF) mRNA and protein in hippocampus of epileptic rats kindled by Pentylenetetrazole (PTZ). Methods: Adult male Sprague-Dawley (SD) rats, weighing (200 ± 20) g, were randomly divided into status epilepticus (SE) group, Control I, chronic epilepsy (CEP) group and Control II. Rats in SE group were initially administrated i. p. with 40 mg/kg PTZ, 10 min later with 20 mg/ kg PTZ, and then with 10 mg/kg PTZ thereafter until the development of SE; rats in CEP group were administrated with 35 mg/kg PTZ for 3 times at an interval of 48 h, until the development of Racine IV-V epilepsy; and rats in Control I and Control II groups were given normal saline in the same manners as SE group and CEP group, respectively. Alternative electro-stimulus Y-maze test was used to evaluate the learning/memory ability of rats; RT-PCR and immunohistochemistry method were used to determine the expression of BDNF mRNA and protein in rats' hippocampus. Results: On the first and second day after kindling, we found that the total errors of rats in SE group were obviously increased compared with those in Control I (P<0.05); the total errors of CEP group on the first, thirtieth and thirty-first day were obviously increased compared with those in Control II (P<0.05). Lower expression of BDNF mRNA and protein in hippocampus was found 1 day after kindling in SE and CEP group and 30 days after kindling in CEP group. Conclusion: Status epilepsy can induce short term deficiency of learning and memory in rats, while chronic epilepsy induces a longer deficiency. Learning and memory deficiency caused by epilepsy might be related to the decrease of BDNF mRNA and protein expression.