The Effect Of Menthol On Rat’learning, Memory And The Expression Of AchE And GluR1in The Hippocampus By The Olfactory Pathways

Background and objectiveAlzheimer’s disease（AD） is clinically common mental illness. Primary foralzheimer’s disease can be divided into senile dementia, vascular dementia and mixeddementia, etc,.the most common is AD. The pathogenesis of AD is very complicated.Since the1906years found that, after more than a century of research, Still have a lot ofissues to be resolved. Current treatments AD to drugs, such as cholinesterase (AchE)inhibitors, can reduce the symptoms in patients with AD, but can not stop the progressof the disease. Olfactory system provide the brain and external environment of thedirect connection, and many of the brain in charge of learning and memory in brainareas are closely related. This makes the olfactory pathways become potential treatmentof learning and memory the effective way of the recession. Aromatic substances such asmenthol is thought to have the effect of refreshing. This experiment is the study of theolfactory pathway and the relationship between learning and memory and through thevolatile aromatic substances of menthol to rat study memory effects to evaluate the rolein the treatment of alzheimer’s disease and dementia. For alzheimer’s treatments providethe theory basis of ofactory pathway and open up the new field of alzheimer’s diseasetreatment and for Aromatic therapy provides the basic theory support.Part One:The neural behavior observation of rats learning memory after suck menthol. MerhodsPut2g menthol in1000ml of hot water fully dissolved with a rat placed in a airtightinfected box in1h for seven days. Application the method of Morris maze of neuralbehavior, through the place navigation tests and the spatial probe tests to observate ratsthe learning change of the space learning and memory.ResultsThe results of the neural behavior show that the SD rats inhalation of menthol comparedwith controls, escape incubation period and platform quadrant retention time forsignificantly less （P<0.05）in the place navigation tests and the spatial probe tests。Itsuggests that through the suck of menthol, the space of the rat space learning andmemory ability obviously improved.Part two:Hippocampus of rats with AchE and GluR1immunohistochemistry observed after suckof mentholMerhodsMorris maze of the place navigation tests and the spatial probe tests showed that the SDrats after suck of menthol compared with controls obviously improve the ability ofspace learning and memory （P<0.05）。In order to observe the relationship between thechange of neural behavior and the neurotransmitter, through the immunohistochemicalmethods to research the change of expression about AchE and GluR1in thehippocampus CA2area in the SD rats after suck of menthol.ResultsThe results of the brain immunohistochemical shows that the SD rats after suck ofmenthol compared with controls the expression significant fall in AchE and GluR1atthe hippocampus area（P<0.01），integral light density values and positive cell numberalso significantly less（P<0.01）. Part two:Molecular Biology Observation of AchE and GluR1in rat hippocampus after suck ofmentholMerhodsTo further observe the neurotransmitter changes, through RT-PCR and ELISA methodsto study the rat hippocampus AchE and GluR1expression level and investigate themechanism that cause rat spatial learning and memory capacity to improve.ResultsThe results of the brain by RT-PCR results shows that the SD rats after suck of mentholcompared with controls the mRNA expression significant fall in AchE and GluR1at thehippocampus area（P<0.01）. The results of the brain by ELISA results shows that theSD rats after suck of menthol compared with controls the expression significant fallabout AchE at the hippocampus area.Conclusion1.The olfactory pathway can improve the SD rats space learning and memory after suckof menthol.2. The results of the brain immunohistochemical and RT-PCR shows that the SD ratsafter suck of menthol through the olfactory pathway the expression significant fall inAchE and GluR1at the hippocampus area. The results of the brain by ELISA resultsshows that the SD rats after suck of menthol compared with controls the expressionsignificant fall about AchE at the hippocampus area.3. Speculation the improve space learning and memory the SD rats after suck ofmenthol through AchE and GluR1together at hippocampus area.