Effects Of Sodium Ferulate On The Learning And Memory Ability Of Aged Rats And The Underlying Mechanisms

ObjectiveThe aim of the study was to investigate the effects of sodium ferulate （SF）on learning and memory ability of aged rats and its possible mechanisms.MethodsForty-five18mon Sprague-Dawley rats, weight500-600g, were randomlydivided into three groups: saline control group, the SF100mg·kg^-1group,200mg·kg^-1group, the group of Sprague-Dawley rats were intragastric the SF of100mg·kg^-1,200mg·kg^-1. Take3mon youth of the Sprague-Dawley rat15,weight250-350g, as young control group. The group of rats intragastric givennormal saline. Intragastric2mon after the Morris water maze test, for sixconsecutive days. After the water maze test, part of the rat cerebral perfusionfixed for immunohistochemical staining observed hippocampal synaptophysin（synaptophysin, SYP）, tyrosine kinase receptor A （tyrosin kinase receptor A,TrkA） and choline acetyltransferase enzyme（choline acetyltransferase, ChAT）in the change. Another part of the rats were quickly taken to the CA3region ofhippocampal in-80°C refrigerator freezing. Western blot analysis ofsynaptophysin （SYP）, choline acetyltransferase （ChAT）, Tyrosine kinasereceptor A （TrkA）, phosphorylation of phosphoinositide dependent kinase1（PDK1）, phosphorylated protein kinase B （Akt） protein levels.ResultsWe examined the effect of SF treatments on learning and memory ability of aged and young rats for the hidden platform water maze task. We trainedrats on a reference memory version of the Morris water maze task with4trialsper day for consecutive5days. Aged and young rats were abled to find theplatform, as indicated by the decrease in escape latencies and the increasedpercentage of time spent in the target quadrant. But, the aged rats showed onaverage longer time to reach the platform and shorter percentage of time spentin the target quadrant than young rats. Compared with aged control-treatedrats, SAaB can siginificantly improve the learning and memory ability of agedrats, shown by shorter escape latency and increased percentage of time spentin the target quadrant. In aged hippocampus, SYP, TrkA, ChATimmunoreactivity was lower. Similar levels were seen in regions CA1, CA3andDG. Aged SF200mg·kg^-1-treated groups significantly increased SYP, TrkA,ChAT protein expression in CA1region, CA3region and dentate gyrus ofhippcampus, compared with the aged control group. The strongest intensity inSYP, TrkA, ChAT immunoreactivity was seen in CA3region of aged SF200mg·kg^-1-treated groups. Western blotting results showed that the basal level ofSYP, TrkA, ChAT, p-PDK1, p-Akt protein expression in hippocampus of agedcontrol group was low in hippocampus. Aged SF100mg·kg^-1and200mg·kg^-1-treated groups significantly inhibited the age control group decrease inSYP, TrkA, ChAT, p-PDK1, p-Akt protein expression in hippocampus of agedrats.ConclutionSodium ferulate can obviously improve the learning and memory ability ofaged rats, this effect may be related to promote the hippocampus of aged ratssynaptophysin protein, tyrosine kinase receptor A and cholineacetyltransferase expression and upregulation of Akt signal transductionpathway.