The Differentially Expressed Genes In Brain Stem Of The Seasickness Susceptible Rats

ObjectiveSeasickness is a kind of Motion Sickness(MS). Signs and symptoms of seasickness include headache, dizziness, nausea, vomiting and many other are less common or obvious, seasickness causes many troubles for the patients. Seasickness has become of increasing interest in recent years because of the development of nautical medicine. Although the proper use of drugs is an effective treatment for seasickness, they have a lot of side effects. People become interested in predicting the seasickness susceptibility. At present, study on the mechanism of seasickness susceptibility is rare. Susceptibility to seasickness varies widely in the population, many researches show that seasickness relates to people's sex, age, race and heredity, so the seasicknes susceptibility is probably related to the genes' differential expression. Many studies on the mechanism of seasickness show that brain stem plays an important role in seasickness. This study aims to screen and identify the differentially expressed genes in sessickness susceptible individuals, and the mechanism of seasickness susceptibility.Methods1. To construct the seasickness susceptible rat modelWe constructed the heat-stressed rat model and compared the kaolin consumption of heat-stressed rats to seasickness rats, for the purpose of using kaolin consumption as the index of seasickness in rats.One hundred Sprague-Dawley (SD) male rats were randomly divided into A group and B group, In each A and B group, 10 rats were picked out randomly as control. Except the control rats, the other rats were stimulated with a stimulator for 1 hour/day. A group rats were stimulated for 3 days, B group rats were stimulated for 21 days. Their seasickness susceptibility were determined and evaluated by the kaolin consumption.The severity of their seasickness was identified according to their kaolin consumption. Rats stimulated of A group were divided into two small groups:seasickness group and non-seasickness group; Rats stimulated of B group were divided into three small groups: seasickness susceptible group, non-seasickness group and seasickness adaptive group.2. Screening differentially expressed genes in brain stem of the seasickness susceptible rats.The tester were the seasickness susceptible rats of B group, the driver were the non-seasickness rats of B group. Suppression subtractive hybridization (SSH) method was used for isolating differentially expressed cDNA in brain stem of the seasickness susceptible rats. The clones were amplified by PCR and identified. The dot blot was used to screen the clones containing inserts. The differentially expressed cDNA was sequenced and analyzed through Genbank.3. To study the relationship between seasickness and the expression of genes in energy metabolismThe rats were stimulated 3 days(A group) and 21 days(B group). The real-time PCR was used to analyze the mRNA levels of ATP synthase, phosphofructokinase, cytochrome oxidase, NADH dehydrogenase and ferritin in brain stem of the different seasickness susceptible rats.Results1. The seasickness susceptible rat modelAfter 3 days of heat exposure, the rats became adaptive to heat-stress. Comparing to the seasickness rats, the heat-stressed rats consumed little kaolin. Before and after the heat-stress adaptation, the amount of kaolin consumption had no difference. But before and after the seasickness adaptation, the amount of kaolin consumption was significantly difference (p<0.05).Between the control group and the test groups, the amount of feed ingestion and the gain of body weight almost had no difference. But the amount of feed ingestion of non-seasickness rats was little higher than the other groups'. At the first few days of stimulation, the control rats' gain of body weight were little higher than the others'.A group rats were stimulated 3 days, the results showed that seasickness rats consumed lots of kaolin, it was significantly higher than the control rats' and the non-seasickness rats (P<0.05). B group rats were stimulated 21 days, the result sh...