Cross-model Research On The Establishment And Regression Of Conditional Fear Emotions And The Repair Of Neural Stem Cell Cross-transplantation

Background and Objectives:Animal model of conditioned fear has been became classical tools for studying the neurological mechanism on emotion related learning and memory.The cross modal of compensation after visual deprivation has become the focus of neuroscience.At present,a large number of studies have confirmed that the primate animal which use visual as the main sensory channel after visual deprivation,of which the capacity of secondary sensory channel compensatory increase,improve visual function through lack of tactile,auditory etc.However,rodents and other rodent animal with auditory and olfactory visual based,supplemented by the model involved in learning and memory,for the advantage of auditory sensory channels after visual deprivation as the "listen" whether cross mode behavior of compensation are to be researched.Factors in the establishment of scholars for visual cues and auditory cued fear conditioning and extinction effect of mood to do a lot of research,but are based on the visual function of the normal situation,to establish a relationship between cross sensory information processing and conditioned fear and extinction has yet to be confirmed.Based on above reasons,our experiment used Opn-/-;rdl/rdl mouse with deficiency in visual as animal model,we aimed at studying the effects of auditory cue stimulus and visual stimulus on acquiring for conditioned fear and extinction in two paradigms in order to seeking theoretical basis for clinical therapy of fear related diseases.Methods:There were two groups:wild group(healthy mouse for 8)and blind group(Opn-/-;rdl/rdl mouse for 8).On the first day,each mouse was habitual training in contextual A and B.On the second day,two groups were trained in contextual A for conditioned fear(voice and foot shock paired showing 5 times);On the third day,two groups were trained in contextual B for conditioned fear extinction(voice showing 10 times without foot shocking);On the fourth day,two groups were trained in contextual B for extinction testing(voice showing 10 times without foot shocking);The percentage of mouse freezing were analyzed and recorded by Freezeframe system.Results:our experiment data showed there were increasing trend for blind group and wild group following with the increased times of stimulus in auditory cue conditioned fear phase and blind mouse received the highest data in CS4 and CS5,showing platform period,there was statistical significance compared with pre training(P<0.05).it indicates that two groups all acquired conditioned fear.There were statistical significance between blind group and wild group(P<0.05),but there is no different interaction effect(P>0.05),which indicated two groups acquired the same degree conditioned fear.In the extinction training,the freezing of mild mouse and blind mouse were significantly different compared with pre training(P<0.05),which indicates two groups acquired extinction in the same degree.In the extinction test,the freezing of mild mouse and blind mouse decreased,and there was significant difference between two groups(P<0.05),but it is different in groups(P<0.05),which indicates blind group and wild group both acquire extinction in the same degree.Conclusions:1.Visual deprivation is more conducive to the establishment of auditory conditioned fear emotion.2.There exists the influence of cross-modal sensory in the process of conditioned fear acquiring.3.secondary sensory(visual)has incentive influence after loss of primary sensory(hearing)in the rodent animal,which is to know a repair and compensatory effect in recognizing environment.4.Visual deprivation impedes the expression of conditioned fear extinction,which suggests that the multiple system combination can not be fully compensated by visual-auditory cross modal.5.There is different influence on the acquisition and extinction of conditioned fear for auditory cue stimulation,which indicates there may be different signal transduction pathway.Background and Objectives:Rhesus monkey neural stem cells(NSCs)are capable of differentiating into neurons and glial cells.Therefore,the transplantation of NSCs can be used to promote functional recovery and clarify the developmental events impacting degenerative diseases of the nervous system.However previous study was mainly focus on the recovery of movement,whether the recognition of brain was influenced is unknown.In addition,a large number of studies proposed the transplantation of stem cells replace the effect of nerve function by differentiating into neurons and glial cells,but for the existence of other mechanisms,such as the effect of cytokines and nerve growth factor,little is known.Based on above condition,we established hippocampus damaged rats model to study the effects of implanted rhesus monkey NSCs and heterogeneity transplantation on spatial learning and memory in hippocampus damaged rats.Through above studying,the effects of rhesus monkey NSCs on recognition was comprehended,providing experimental basis and theory for seeking clinical therapy in the future.Methods:1.bilateral dorsal hippocampus was damaged by direct electrical stimulus equipment so as to establishing hippocampus damaged rat model.2.rhesus monkey NSCs was prepared by the method of EB and embryonic,then NSCs was transplanted into the damaged hippocampus to establish transplantation model.3.Balance test and prehensile test were applied to test the hippocampus damaged model.and Morris water maze test was used to test the spatial learning and memory ability for the Control,Sham,Lesion,Vehicle and NSCs group.4.Preparing HE slides and observing the histological structure of damaged hippocampus and the transplanted rhesus monkey NSCs under laser confocal fluorescence microscopy.Results:1.In balance test and prehensile test,there was no significant difference between each groups(P>0.05),indicating the model for hippocampus damage is successful.2.The Morris Water Maze test shows the escape latency for each group decreased gradually following the lasting time of experiment.Compared to Vehicle and Lesion group,the average escape latency for NSCs group decreased prominently in 4 to 8 days,it shows statistical difference(P<0.01).In the spatial probe test,compared to Sham group,the average time of crossing platform decreased obviously for Lesion group and Vehicle group,and there was significant difference(P<0.01).Compared to Vehicle and Lesion group,NSCs group shows increasing time of crossing platform and there was statistical difference(P<0.01).The crossing time for Vehicle.has no difference compared with Lesion group(P>0.05).In the spatial probe test,the crossing time of platform for Vehicle and Lesion decreased and there was statistical difference compared to Sham group(P<0.01).The swimming percentage for NSCs group in the target quadrant was not higher than Control and Sham group,and it has no difference compared with Vehicle group(P>0.05),but there was statistical difference compared to Lesion group(P<0.05).3.Microscopically the hippocampus structure of model group was not intact,which showed the lesion was located in the dorsal hippocampus and around,with cell destroying,shortage and disorganizing.Under laser confocal fluorescence microscopy,rhesus monkey NSCs showed that Nestin was positive after culturing 12 days.Under dedifferentiated condition,cells showed filiform structure and form morphological characteristics of long axon,showing ??-tubulin was positive.Additionally most of the transplanted cells grew well,part of cells living on the surface of brain cortex and integrating into parenchyma of the recipient brain.Conclusions:1.the model for hippocampus lesion is successful.2.NSCs transplantation can obviously improve the spatial learning and memory abilities in rats with hippocampus lesions.3.The transplanted NSCs could express NSCs marker,being alive in the brain of rat,and can integrated into the host brain.