ABSTRACT
Objective To establish the model of traumatic brain injury in rats with controlled cortical impact (CCI), and investigate the features of coma and cognition. Methods 40 male Sprague-Dawley rats were randomly divided into control group (n=10), sham group (n=10) and CCI group (n=20). CCI group was impacted at bilateral frontal lobe with the velocity of 3.5 m/s, depth of 7 mm and dwell time of 250 ms. The time of consciousness loss was recorded, and all the rats were investigated with Morris Water Maze 10 and 20 days after opera-tion. Results The time of consciousness loss was longer in the CCI group than in the control group and the sham group (P<0.001). The es-cape latency was longer in the CCI group than in the control group and the sham group (P<0.001), while the percent of time spend in goal quarter during probe trial was less (P<0.001), both 10 days and 20 days after operation. Conclusion CCI at bilateral frontal lobe of rats can establish the model of severe traumatic brain injury with coma and long-term cognitive dysfunction.
ABSTRACT
Objective To evaluate the method of controlled cortical impact(CCI) on long term cognitive disorder after traumatic brain injury(TBI) and to investigate the possible pathological mechanism.Methods Sixty male SD rats were randomly assigned into 3 groups:sham surgery group(n =10),control group (n =10) and CCI group(n =40).CCI application was used to make the bilateral frontal lobe controlled cortical impact model (depth:1.5 mm,velocity =3.5 m/s,dwell time =400 ms).Morris water maze test and Nissl's staining was used to assess the cognitive function and pathological changes after 8 weeks of CCI.The expressions of brain derived neurotrophic factor (BDNF) and tyrosine protein kinase B (TrkB) mRNA in frontal lobe and hippocampus tissue was detected by reverse transcription polymerase chain reaction(RT-PCR).Results The mortality in CCI group was only 12.5％.Morris water maze test results showed the escape latency in CCI group was longer than that in sham surgery and control groups(F =51.784,P ＜ 0.05).Percent of time spend in goal quarter during probe trial in CCI group was significantly less than that in sham surgery and control groups(F =13.468,P ＜ 0.05).Nissl's staining showed frontal lobe had obviously defects; Nissl's bodies of frontal cortex and CA1 region in hippocampus reduced.The expressions of BDNF and TrkB mRNA in frontal lobe and hippocampus were significantly less than those in sham surgery and control groups(P ＜ 0.05).Conclusions The CCI model can be applied for study on long term cognitive disorder after TBI with good stability and repeatability.Using the experimental parameters of CCI can damage the long term cognitive function after TBI in rats,and lead the pathology changes of brain tissue clearly.This may have some relationship with the expressions of BDNF and TrkB mRNA.
ABSTRACT
@#Objective To establish the model of traumatic brain injury in rats with controlled cortical impact (CCI), and investigate the features of coma and cognition. Methods 40 male Sprague-Dawley rats were randomly divided into control group (n=10), sham group (n= 10) and CCI group (n=20). CCI group was impacted at bilateral frontal lobe with the velocity of 3.5 m/s, depth of 7 mm and dwell time of 250 ms. The time of consciousness loss was recorded, and all the rats were investigated with Morris Water Maze 10 and 20 days after operation. Results The time of consciousness loss was longer in the CCI group than in the control group and the sham group (P<0.001). The escape latency was longer in the CCI group than in the control group and the sham group (P<0.001), while the percent of time spend in goal quarter during probe trial was less (P<0.001), both 10 days and 20 days after operation. Conclusion CCI at bilateral frontal lobe of rats can establish the model of severe traumatic brain injury with coma and long-term cognitive dysfunction.
ABSTRACT
ObjectiveTo investigate the effect and gender differences of experimental moderate pain on attentional bias towards pain-related words.MethodsWith the tourniquet around the left upper limb,32 healthy college students were asked to perform two dot-probe tasks including five kinds of pain-related words,one task with the tourniquet deflating and the other task with the tourniquet inflating to 200 mm Hg pressure.The reaction time (RT) and the error rate of recognition task were recorded.The pain intensity and distress were recorded too.Results ( 1 ) Compared with no pain condition ( RT of affective and social-threat words were (507 ± 78 ) ms,(504 ±89 )ms respectively),the react time was shorter in female in the condition of tourniquet pain,particularly for affective and social-threat words (the RT were (464 ± 79 )ms,(465 ± 72 )ms respectively,F ( 1,4) =19.157,P ＜0.01 ),but not in male.( 2 ) In condition of no pain,the reaction time of male ( (456 ± 59) ms ) was shorter than that of female (504 ± 79ms).However,in the condition of pain,the significant main effect was not found.ConclusionThe reacting time of female was shorter in condition of moderate tourniquet pain,which imply that female showed significant attentional bias towards affective and social-threat words.