The Effect Of Exercise-induced Fatigue To Rats' Learning And Memory In The Environment Of Plateau

ObjectiveTo instigative the effect of exercise-induced fatigue to rats'learning and memory in the environment of plateau.MethodsTreadmill training was adopted to set up the model of Rats' high intensity exercise. 32 healthy adult Wistar rats were randomly divided into four groups:Lanzhou control group(LA),severe fatigue group in Lanzhou (LZ),plateau control groupg in kekexili (KA),severe fatigue group in plateau of kekexili (KZ). The rats in plateau of kekexili were taken from Lanzhou to kekexili plateau (4767m) using automobile. The behaviors of rats were studied in Morris maze test, recording the escape latency, distance exploration, swimming path to find the hidden platform and the times across plot in 120s。ResultsThe escape latency of control group groups and severe fatigue group were 54970.00±15899.06 ms.81076.00±19217.30 ms in Kekexili groups and 45655.00±23178.86 ms,59207.0±18671.67 ms in Lanzhou groups. The distance exploration of control groups and severe fatigue groups were 12.77±3.30m,18.09±3.76 m in Kekexili groups and 11.73±5.95m,15.20±4.48m in Lanzhou groups.As compared with those of the Lanzhou groups, the escape latency of Kekexili groups increased (P<0.05),The difference reached the climax in severe fatigue group (P<0.01).The times across plot of control groups and severe fatigue groups were 2.38±0.92,0.88±0.83 in kekexili groups and 4.50±1.51,2.63±1.30 in Lanzhou groups, As compared with those of the Lanzhou groups, the escape latency of Kekexili groups decreased (P<0.01).Conclusion exercise-induced fatigue in the hypoxic plateau environment may have significant influence on the ability of learning and memory in rats. High altitude hypoxia and severe fatigue can influence learning and memory in rats to a certain in extent。ObjectiveTo instigative the expression of NR2B in the rats' hippocampus after exercise-induced fatigue in high-altitude environment, using the DNA home position terminal sign notation to examine neurons apoptosis in hippocampal CA1 region of rats.MethodsTreadmill training was adopted to set up the model of Rats'high intensity exercise.32 healthy adult Wistar rats were randomly divided into four groups:Lanzhou control group(LA),severe fatigue group in Lanzhou (LZ),plateau control groupg in kekexili (KA),severe fatigue group in plateau of kekexili (KZ). The rats of group in plateau of kekexili were taken from Lanzhou to kekexili plateau (4767m) using automobile. The immunohistochemistry was used to detect the contentrition of NR2B in hippocampus. using the DNA home position terminal sign notation to examine neurons apoptosis in hippocampal CA1 region of rats.Results1. The number of positive cells of NR2B of control groups and severe fatigue groups were 67.625±7.308,49.25±4.559 in Kekexili groups and 148.88±7.809 120.50±9.78 in Lanzhou groups. As compared with those of the Lanzhou groups, the content of NR2B decreased in kekexili groups (P＜0.01).2. The number of apoptotic neurons cells in the hippocampus CA1 in the control groups and severe fatigue groups were:69.58±6.50,100.92±6.98 in kekexili groups and 27.58±2.89,32.00±2.32 in Lanzhou groups.The number of apoptotic cells in hippocampal CA1 neurons in the kekexili group was higher than the Lanzhou group (P＜0.01), The number of apoptotic neurons cells in the hippocampus CA1 was significantly increased between kekexili groups and Lanzhou groups (P＜0.01).ConclusionExercise-induced fatigue of hypoxic exposure in high-altitude environment may have reduced the expression of NR2B in hippocampus, the decline of learning and memory ability of rats may be related to the decline in NR2B expression in hippocampus and apoptosis of hippocampal neurons cell.ObjectiveTo investigate the influences of exercise-induced fatigue to rats' cognition and the ultrastructure in CA1 region of the hippocampus in the Environment of plateau; Meanwhile, observe the effects of ginsenoside Rd on cognition and the ultrastructure in CA1 region of the hippocampus in exercise-induced fatigue to rats'in the Environment of plateau。MethodsTreadmill training was adopted to set up the model of Rats' high intensity exercise. 24 healthy adult Wistar rats were taken from Lanzhou to kekexili plateau (4767m) using automobile, randomly divided into three groups:saline control group(group A),severe fatigue of saline control group(group B),severe fatigue group of ginsenoside Rd (group C)。Rats in control group (group A) were raised normally, treadmill training was adopted to set up the model of Rats of high intensity exercise; severe fatigue group of ginsenoside Rd (group C) were given ginsenoside Rd (2mg/kg). control groups and severe fatigue groups of saline group were given normal saline(2mg/kg). The learning and memory ability of rats in each group were assessed with the Morris water maze test(MWM) at the end of the experiments, record the escape latency, distance exploration, swimming path to find the hidden platform and the times across plot in 120s. Using HE staining to observe histological changes in the hippocampus; The ultrastructure of hippocampal neurons was observed by electron microscope after the completion of the experiment.Results1. The analysis of data of Place navigation test:The escape latency of the three groups were become shorter with the increase of the times of exercise, The escape latency of group B was 81.076±19.217 s,which is longer than group A (54.970±15.899) s(P< 0.01);The escape latency of group C was 69.001±18.178 s, which is shorter than group B (P< 0.05); and there was a big difference between severe fatigue group of saline control group and severe fatigue group of ginsenoside Rd (P<0.05). The analysis of data ofSpatial probe test:the times across plot in 120s of group A was 2.38±0.92;signicantly more than group B(0.56±0.24) (P<0.01); the times across plot in 120s of group C were more than those of group B (P< 0.05).it means severe fatigue have bad influence to the rats' learning and momery. ginsenoside Rd could improve it.2. From microscope observe morphological changes through HE staining: hippocampus cells of the rat of group A keeps normal; the neurons were arrayed in good ordered. group B in rat hippocampus organizations become swelling, the gap around cells become widened, cell bodies became round and larger, the staining of cytoplasmic become shallow,even disappears; the neurons were loosely arrayed and some were disarrayed, the connections among neuron were decreased and some neurons were shrinked,Cmpared with the rats of group B, the swelling of neurons of group C have become improved.3. ultrastructural changes in the electronic electron microscope: In the electronic electron microscope, the structure of neuron cell in hippocampal CA1 of rat in group A keeps basically normal, the organelles of cytoplasmic keeps basic integrity, arranged orderly. Mitochondrial size and shape were normal.but the number of organelles have a relative reduction, especially in rough endoplasmic reticulum.The neuron cell in hippocampal CA1 of rat in group B have become swelling, the number of organelles have a significant reduction and scattered, mitochondrial swelling and rupture and partial integration disappears can be seen, membrane rupture dissolved. There are bite nerve phenomena, the surface phenomena of severe degranulation, some nuclear were shrinked, peripheral vascular swelling significantly.Comparing with the rats of group B,the rats of groupC have a less pathological changes, neuron of hippocampal CA1 area is still normal, the number of organelles keeps normal, cell swelling and organelle swelling have improved, endothelial cells is still keeps normal.ConclusionIn the environment of plateau, there was close correlation between cognitive disorders that exercise-induced fatigue lead to rats and the changes in the ultrastructure of hippocampal neurons. Severe fatigue can lead to damage in rat hippocampus neurons, causing histomorphology changes in hippocampus neurons; Ginsenoside Rd could improve the damage of hippocampus ultrastructure and rats' learning and memory...