| ObjectiveTo prepare chronic simple animal model Of terror stress in adult female rats by the method of watching other rats shocked by electricity、surviving in danger and imitating earthquake, Through the observation of the general situation and the pregancy and delivery in mother rats and the growth and developmentin rat offspring, and the test of the hippocampus morphology and molecular biology change and spatial learning and memory capacity in rat offspring, screen the best modeling method, and the preliminary discussion was held on the effect of terror stress in adult female rats on the spatial learning and memory abilities and the molecular mechanism.MethodWistar rats (60female,40male) were involved(SPF:2-month-old), the weight was180±20g. According to random number table method,60female rats were average divided into electric shock group, survive in danger group,the imitating earthquake group and blank control group.30male rats with larger weight were selected as mating rat from40male rats, the remaining10as shock rat.From the first day modeling shock rats and onlooker rats in watching other rats shocked by electricity group were put into the corresponding small indoor of Autonomous exchange box at9:00AM, shock10times/d,3min/time; From the first day surviving rats in surviving in danger group were put into the Autonomous danger box at9:00AM, shock ltime/d,30min/time; From the first day the rats in imitating earthquake group were put into the gas oscillator bath at9:00AM, shock10times/d,3min/time. At9:00on the15th day put the rats together into the same cage by female and male2:1. Check the conception situation at7:00AM the next day, make model till pregnant the19th day. During modeling time female mice in blank control gruop were put into the quiet environment for30min. After the production of mothers10nests every group,8rats every nest were selected to feed and to do the experiment.2rats in every nest each group were selected randomly on the14th,21th day respectively,after the anatomy,take hippocampal organization as the detection.2one-month rats each group every nest were chosen to make the morris on water maze experiment Observation and detecting indicators:(1) the general situation and the pregnant production situation;(2)the growth and development situation of rats such as emancipation,teeth;(3) observe pathological changes of the hippocampus nerve cells synaptic ultrastructure in14-day old,21-day old rats in electron microscopy;(4) detect the protein expression of CREB, SYN-1of the hippocampus’p-CA3in21-day old rats by immunohistochemical method;(5) test the spatial learning and memory capacity of1-month rats by Morris water maze.Results1Animal model of terror stress in adult female rat:Three chronic simple animal model of terror stress in adult female rats were produced successfully.2The changes of terror-injured adult female rats’situations:compared to the blank control group, fur colour and lustre、the degree of quick reaction、the activities flexibility、mental state of female rats in the model group obviously became poorer,The abnormal degree declined on the sidelines of watching other rats shocked by electricity group、surviving in danger groupand imitating earthquake group.3The mother rats’pregnancy:compared to the blank control group.Children size in the model group reduced、differences showed statistical significances (P<0.05) Children size、pregnant rats’size、pregnant rats’size in every model group, the differences between each group showed no statistical significance (P>0.05)4The situation of terror-injured adult female rats’growth:compared to the blank control group, the time of the rolling、growing teeth and opening eyes in the model group rats extended, the differences showed statistical significances (P<0.05) Between the model group, differences between them showed no significance (P>0.05)5The pathological changes of hippocampus nerve cells synaptic ultrastructural in terror-injured adult female rats and infant rats:brain nerve cells synaptic vesicles in hippocampus and mitochondria in model group rats change differently. Thechanging degree declined on the sidelines of watching other rats shocked by electricity group、 surviving in danger groupand imitating earthquake group.6the protein expression of CREB, SYN-1of the hippocampus’p-CA3in21-day old terror-injured adult female rats:compared to the blank control group, the protein expression of p-CREB, SYN-1in hippocampal CA3area in watching other rats shocked by electricity group、surviving in danger group reduced.Difference showed statistical significance.(P<0.05), the difference of imitating earthquake group showed no statistically significance (P>0.05);compared to the watching other rats shocked by electricity group,the protein expression’ sdifference of p-CREB, SYN-1in imitating earthquake group showed statistically significance (P<0.05); The differences of surviving in danger group showed no statistically significant(P>0.05); compared to the surviving in danger group, the protein expression’s difference of p-CREB, SYN-1in imitating earthquake group showed statistically significance (P<0.05)7The impacts of terror stress in adult female rats on the spatial learning and memory capacity of1-month rats:(1) Compared with the control group, the mean escape latency was prolonged in the watching other rats shocked by electricity group for4days, with significant differences (P<0.05); the mean escape latency of surviving in danger group and imitating earthquake group on1st day extended, the other three days get shorter, differences showed no statistically significance,compared to watching other rats shocked by electricity group, the four days of mean escape latency are shorter, differences showed statistical significance (P<0.05).Compared surviving in danger group with imitating earthquake group, the differences of the mean escape latency for four days showed no statistical significance (P>0.05);(2) Compared with those in the control group, infant rats in the model group chose non-effective strategies more, and significant differences were found (P<0.05); significant differences between other groups were not found (P>0.05);(3) In spatial probe test, compared with the control group, the average speed of the model group was slower (P<0.05), the percent of swimming distance in the20%rim quadrant increased (P<0.05), but decreased in other quadrant (P<0.05), the average swimming speed of imitating earthquake group was slower,other differences showed no statistical significances (P>0.05); compared to watching other rats shocked by electricity group, the differences of the average swimming speed of surviving in danger group、the20%rim quadrant and other rim quadrants showed statistical significances (P<0.05), the difference of imitating earthquake group showed no statistically significant difference (P>0.05); the differences between surviving in danger group andimitating earthquake group showed no statistically significance.(P>0.05)Conclusion1In three fear-injured kidney animal models、method of watching other rats shocked by electricity are most suitable.2The terror-injured adult female rats not only can affect their breed, but also cause the pathological changes of nerve cells in the hippocampus, synaptic change and rat spatial learning and memory capacity reduction.3The possible mechanism of effect of terror stress in adult female rats on the spatial learning and memory abilities as well as hippocampus neural synapses in rat offspring:terror-injured adult female rats cause the rat hippocampus CA3-CERB decrease, cause the reduction of SYN-1downstream expression, furtherly influence the changes of hippocampus synaptic,which eventually led to the abnormal hippocampus structure and function. |
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