Screening And Verification Of Differentially Expressed Genes Base The Motion Sickness Susceptibility Model

Motion Sickness(MS)induced by abnormal acceleration stimuli result in series of vegetative nervous system symptoms.Previous reported that sex and age are two main predictors of motion sickness susceptibility in general populations.The epidemiological data highlight the importance of genetic factors in determining an individual's susceptibility to motion sickness.Over-stimulation of vestibular organs resulting in activation of vestibularvisceral pathways can change the plasma hormone levels and neuronal activity.But the mechanism of how motion sickness occurs is unclear.In the present study,the potential correlates of vestibular-autonomic pathways with sex and age differences in rats with motion sickness were investigated.Motion sickness was assessed by measurement of autonomic responses(i.e.,conditioned gaping and defecation responses),motor impairments(i.e.,hypoactivity and balance disturbance)after Ferris wheel-like rotation,and blood hormone levels and central Fos protein expression were also observed.Microarray analysis was used to screen differentially expressed genes in the caudal vestibular nucleus(CVN)after rotation(Rot)in MS susceptible(MSS)and insusceptible(inMSS)rats.Finally,the relationship of the activity of down-streamsignal transduction pathways and SNP of Olr81(OR52J3)receptor with MS susceptibility was examined,and through in vitro experiments to verify the connection.Contents:1.The correlates of vestibular-autonomic pathways with sex and age differences in rats with motion sicknessTo observe change of conditioned gaping,defecation responses,motor and balance beam test,blood stress hormone levels and Fos protein expression in rats after rotation.2.Establishment of MS animal model and MS susceptibility evaluation for microarray experimentUsing microarray analysis and real-time quantitative-PCR to identify differentially expressed genes in the CVN on MS susceptibility model.Then,to determine the gene through functional antagonism or manipulation of gene expression level by using an in vivo Elvax implantation method;3.The relationship between the activity of signal transduction pathways and SNP of Olr81(OR52J3)receptor with MS susceptibilityTo observe the distribution of Olr81 receptor and G?olf in CVN by immunohistochemistry,and the change of enzyme activity and second messenger level in MSS and inMSS animals after roation.Lastly,to verify the SNP of Olr81 connection with MS susceptibility.Results:1.Rot-induced gaping was significantly decreased at group of 13 or 14 months age compared with other month-age groups in both males and females.Rot treatment can not induced a sex difference in conditioned gaping across ages.Females had higher defecation responses after rotation than males at 1,4,and 13 months of age.There was a significant age-related increase in blood epinephrine and norepinephrine levels.Compared with Sta controls,rotation stimulation significantly increased the numbers of Fos-LI neurons in the MVN,the SpVN,the NTS,the Ce A,the LC and the Me A in male and female animals.The numbers of Fos-LI neurons in the NTS and the PBN were significantly higher in Rot females than Rot males at 4 and 13 months of age.The numbers of Fos-LI neurons in the LC and the PVN were also significantly higher in Rot females than Rot males at 13 months of age.2.Microarray analyses identified a total of 304 transcripts differentially expressed in the MSS-Rot group compared to the inMSS-Rot group.Additionally,though signal-net analysis and GO analysis significant signaling pathways(n=10)were found.Olr81,Shc1,Chrna3,Htr4,Tacr1 and Gabra6 were finally selected as the candidate genes for the following experiment.The MSS-Rot/ inMSS-Rot ratio of gene expression for the nAchR ?3 subunit,5-HT4 R,NK1R,the GABAAR ?6 subunit,Olr81 and Shc1 were similar to the ratios obtained by microarray analysis.Inhibiting the expression of Olr81 in vestibular nucleus can alleviate the response of motion sickness to rotation.3.The results showed that there are mass of Olr81 and G?olf expression in the CVN.Rotation can increase the activity of AC/cAMP/PKA pathway and decrease the activity of PLC(PI3K)/PI3 pathway.There are different genotypes with different motion sickness susceptibility.The mutations in the C903 T of rs57026471 in human OR52J3 could be related to the susceptibility to motion sickness.The mutation can significantly increase the intracellular calcium influx of OR52J3 under agonist action.Conclusion:1.An age-related alleviation in motion sickness-related gastrointestinal responses(nausea and defecation)and motor disorders(hypoactivity and balance disturbance)was found.The age-related decline in motion sickness susceptibility might be mainly attributed to the activity changes in neurons of the vestibular and autonomic areas;2.Our findings suggested that the variability of the CVN gene expression,especially Olr81,profile after motion stimulation might be a putative molecular basis for individual differences in MS susceptibility;3.The SNP in Olr81(OR52J3)gene is associated with MS susceptibility.