Effects of astrocyte activation in cognitive impairment after traumatic brain injury
Objective To explore astrocyte activation's impact on cognitive deficits post-traumatic brain injury(TBI).Methods SPF male rats were divided into control,sham-operation and model groups with 10 rats per group.Control group did not receive the surgical intervention;sham-operation group underwent craniotomy without damaging the dura mater;model group was struck with brain injury instrument after craniotomy.The rats with knockout overexpressed glial fibrillary acidic protein(GF AP)gene were set as the knockout group and overexpression group,with 10 rats per group.The knockout and overexpression groups were treated as the model group.Neurological function was evaluated by modified neurological severity score(mNSS).Escape latency was assessed with the Morris water maze test.The expression levels of GFAP in astrocytes were measured quantitative real-time polymerase chain reaction.The positive expression of astrocytes was determined by immunohistochemistry.Results The mNSS of control,sham-operation,model,knockout and overexpression groups were 0,0,(9.60±1.17),(15.20±1.55)and(12.00±1.33)points;the escape latency period at day 7 was(16.15±2.48),(16.98±2.35),(40.72±5.42),(75.42±8.59)and(47.23±6.04)s;the number of positive astrocytes was(1 264.60±135.45),(1 289.20±132.29),(3 269.10±189.39),(103.90±11.09)and(5 301.50±236.29)cell·mm-2;the expression levels of GFAP gene in control,sham-operation,model and overexpression groups were 0.86±0.02,0.92±0.04,1.37±0.07 and 3.42±0.07.Compared with overexpression group,the differences of above indexes in control,sham-operation,model,knockout groups were statistically significant(all P<0.05).Conclusion TBI causes cognitive impairment and affects cognition and memory in rats,and the GFAP gene is associated with the activation of astrocytes and helps repair nerve damage.
astrocytestraumatic brain injurycognitive impairmentMorris water maze testescape latency