The Cognition Changes of Pure and Multiple Cerebral Concussions in Rats Model at 1, 3 and 6 Months after Injury / 中国运动医学杂志

ABSTRACT

Objective To detect the long term effect of pure and multiple concussions on spatial cognitive of rats.Methods One hundred and eighty 7-week-old Spragne-Dawley male rats with weight of 280 ± 30g were chosen and randomly divided into a control group and a concussion group.The cerebral concussion was induced in the rats using a metallic pendulum striker concussive device.After the first strike,the brain injury group was randomly divided into a pure cerebral concussion(PCC)group and a multiple cerebral concussion(MCC) group.After the second strike,the MCC group was randomly divided into two-fold cerebral concussion(2MCC) group and three-fold cerebral concussion(3MCC) group.The striking interval was 24h.One,3 and 6 months after trauma,their cognitive function was tested using Morris water maze.Results One month later after injury,there was no significant difference in the escape latency between the control group and PCC group.Significant differences in the measurement were observed between the control/PCC group and 2MCC group on the 7th day after the injury,also between the control/PCC and 3MCC groups on the 6th and 7th day.And there were significant differences between the 2MCC and 3MCC groups on the 6th and 7th days.The non-platform test did not observe any significant differences among the four groups.Three months after injury,there was still no significant difference between the control group and PCC group,PCC and 2MCC groups,as well as 2MCC and 3MCC groups in the escape latency.However,there was significant difference between the control group and 2MCC group on the 5th,6th and 7th days,between the control group and 3MCC group on the 4th,5th,6th and 7th days,as well as between PCC group and 3MCC group on the 6th and 7th days.In the non-platform test,there was no significant difference between the control group and PCC group,between PCC group and 2MCC group,as well as between 2MCC group and 3MCC group.However,2MCC and 3MCC groups spent significantly less time in the former platform quadrant,when compared with the control group and 3MCC group spent significantly less time than PCC group.Six months after injury,significant differences in the escape latency were observed between the control group and PCC group on the 6th and 7th days,and 2MCC group on the 5th,6th and 7th days,also and 3MCC groups on the 2nd,3rd,4th,5th,6th and 7th days,still between PCC group and 2MCC group on the 6th and 7th days,as well as between PCC group and 3MCC group on the 4th,5th,6th and 7th days.Moreover,there was significant difference between 2MCC and 3MCC groups only on the 7th day.In the non-platform test,PCC group,2MCC group and 3MCC group spent significantly less time in the former platform quadrant compared with the control group.Moreover,in this test significant differences were found between PCC group and 2MCC/3MCC group,but not between 2MCC group and 3MCC group.Conclusion With the increase of cerebral concussion times,earlier and more serious damage of spatial cognition will appear,with a significant cumulative effect in rats.Such rat model can be used to study the pathological changes of cognitive impairment in chronic traumatic encephalopathy.