The Effect Of Rosemary Treatment On Learning And Memory’s Improvement And Content Of5-HT And GABA Of Hippocampus Through Olfactory Pathway In VD Rats

ObjectiveIn this study,we established rat VD model after chronic cerebral ischemia by modifiedligaturing bilateral common carotid artery. In order to study the effect of rosemarytreatment on learning and memory impairment caused by VD through olfactorypathway. On the other hand, in order to test the changes of5-HT and GABA in thehippocampus of VD rats after treated by rosemary with immunohistochemistry methods.Primarily to study the effect and mechanism and clinical application of rosemary treatedon learning and memory impairment caused by VD through olfactory pathway.Methods1.Preparing VD rat model. Establishing rat VD model by modified ligaturing bilateralcommon carotid artery, namely as the left common carotid occlusion with a week laterligatured the right one.2.Model rat screened by Morris water maze.4weeks after the surgery,there were16model rats, normal rats and sham operation rats were both8. The learning and memorycapacity of32rats was tested by Morris water maze.In this test,the escaping latency ofthe rats to find the hidden platform in orientation navigate test and the numbers of ratscrossing the former platform in spatial probe test were recorded.The time was limitedwithin120seconds.3.Dividing rats and Drug delivery. Modele rats were randomly divided into modelgroup and rosemary group, and the normal group and the sham sham operation groupwere separated to control.(1) rosemary group(n=8):this group were treated witheugenol(the consistence is1%)3days after surgery twice a day， and each time lasted30minutes.(2) VD model group (n=8): rosemary essential oil were replaced bydistilled water, Then the rats in this group get the same procedures as the rosemary group.(3) sham operation group (n=8): the rats in this group submitted to the bilateralcarotid arteries were Isolated but not ligatured, Then the experiment steps were samewith VD model group;(4) normal group (n=8): the rats were not gave surgery andtreated with rosemary.Then the rats in this group also got the sameprocedures as the VD group.Result1.4weeks after surgery, there was significant differences between operation group andnormal group in the latency and the times through platform(P<0.05). There wasunsignificant differences between sham operation group and normal group in thelatency and the times through platform (P＞0.05).2.5weeks after treatment, there was significant differences between rosemary groupand VD group in the latency and the times through the former platform (P<0.05).Aslo compare to normal control group，VD group had significant differences in thelatency and the numbers through the former platform (P<0.05).3. In the results of immunohistochemistry,compare to normal control group, in thehippocampus of VD group rats were significantly decreased (P<0.05). Also the contentof5-HT and GABA in the hippocampus between the treatment group and VD grouprats were significantly different(P<0.05).Conclusion1.The VD rat model produced by the modified2VOM had less traumatic brain injury,but with significant learning and memory impairment. This is fitting with the clinicalfeatures of VD.2. After the treatment of rosemary through olfactory pathway, learningand memory dysfunction of rats with VD could be improved.3. The mechanism ofrosemary improving learning and memory impariment of VD rats was related to theincreaseing of the content of5-HT and GABA of Hippocampus.