[Effect of ecdysterone on the expression of c-fos in the brain of rats induced by microinjection beta-AP25-35 into the hippocampus].
OBJECTIVE
To observe the behavior in learning and memory and the expression of c-fos gene from the brain of rats induced by beta-AP25-35, and the intervention of ecdysterone, in order to explore the protective mechanism of ecdysterone on the dysfunction of learning and memory of the rat induced by beta-AP25-35.


METHODS
Microinjection of beta-AP25-35 into hippocampus induced learning and memory dysfunction of rats. The learning and memory of rats were observed by Morris Water Maze. The expression of c-fos gene in the brain was detected by immunohistochemistry.


RESULTS
The results of Morris Water Maze showed that after rats were microinjected beta-AP25-35 into hippocampus, the rats in model group took longer latency and searching distance compared with the ones in control group (P < 0.01), and the rats in treated group (ECR 4 mg x kg(-1), ECR 8 mg x kg(-1) and nimodipine 7.2 mg x kg(-1)) took shorter latency and searching distance, especially the ECR 8 mg kg(-1) group (P < 0.01). At the same time, after the 5 days training, there was a higher expression of c-fos in hippocampus and cortex from the rats in control group than that in model group (P < 0.01), but in the treated group, there was a relatively higher expression of c-fos, especially the ECR 8 mg x kg(-1) group (P < 0.01).


CONCLUSIONS
Microinjection of beta-AP25-35 into the rat hippocampus resulted in dysfunction of learning and memory. Ecdysterone was shown to improve the learning and memory of the rats and increase the expression of c-fos. Increasing the expression of c-fos is probably one of the most molecular mechanism of its protection.
Department of Pharmacology, Chongqing Medical University, Chongqing 400016, China.
Su-fen
SF
Yang
Zheng-qin
ZQ
Yang
Qi-xin
QX
Zhou
Qin
Q
Wu
Xie-nan
XN
Huang
Jing-shan
JS
Shi
D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000633:toxicity; D000818:Animals; D004441:Ecdysterone / Q000494:pharmacology*; D015870:Gene Expression; D016762:Genes, fos; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008845:Microinjections; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000633:toxicity; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D016760:Proto-Oncogene Proteins c-fos; C074636:amyloid beta-protein (25-35); D004441:Ecdysterone