| Traumatic brain injury (TBI) is the chief cause of death in the people younger than 45 years. The main pathological phenomena of TBI and Diffuse axonal injury (DAI) is associated with high mortality and morbidity. Evidence provided by the Traumatic Coma Data Bank in USA shows that 55% of patients comatose on admission suffered from DAI. The DAI is not suitable for operation; so many neuroprotective agents are recommended. Thus, neurotrophic factor (NTF) is one of the most important focus in present researches. Since neurotrophic factors contribute greatly to the the development of nervous system and process of reparative regeneration post injury, they offer a new hope to the treatment and prevention of nervous system diseases. Candidate plasticity-related gene 15 (CPG15) is a new member of NTFs, which could be induced by neural activity and other NTFs. And cpg15 encodes a protein that regulates dendritic and axonal arborgrowth and synaptic maturation.The research investigated the expression and significance of CPG15 in frontal brain cortex of rat DAI model at different post traumatic, due to lateral head rotation .1.The establishment of the DAI animal modelObjective To set up a DAI animal model in rats. Methods male SD rats were divided randomly into two groups: normal and DAI group. The DAI model was produced by lateral head rotation device. Then the rats were tested for HE stain, the motor and cognitive performance 12 hours post injury and measured for the water content of brain tissues. Results The NSS of rats with DAI ascend noticably; The water content of brain tissues of DAI groups increased obviously at 1 d post injury. Then, it decreased gradually, and reached the normal level at 14 d. Conclusion The successful establishment of this model can provide solid foundation for the following study.2. The research of the CPG15 post DAIObjective To investigate the expression and significance of CPG15 (candidate plasticity-related gene 15) in frontal brain cortex of rat model at different time point post diffuse axonal injury (DAI). Methods The 81 male SD rats were divided randomly into normal control group (n=27) and DAI group (n=54). The DAI model was produced by lateral head rotation device. Thrity-six rats in DAI group were subdivided into 1 d,4 d,7 d,10 d,14 d,21 d subgroup with 6 each for immunohistochemistry (The occurrence of yellow-brown dusts was considered as"positive", and the lack of these objects as"negative"). The rest rats in DAI group (n=18) was subdivided into 7d,14d,21d group with 6 each for both Western-blot and RT-PCR. The expression of CPG15 in the cortex in rat frontal brain was investigated by immnohistochemical method, and Western-blot and RT-PCR. Result No expression was found in frontal cortex in normal rat brain. The expression of CPG15 occurred in small amount in the frontal cortex in the rat 1 day post DAI. The neuronal expression of CPG15 became stronger gradually at 1, 4, 7 and 10 d, reached to the peak at 14 d and maintained a higher level at 21d. It remained at the higher level at 21 d post DAI. The CPG15 protein level and the CPG15 mRNA level changed in asimilar tendency and peaked at 14 d. Conclusion The results show that the upregulation of CPG15 expression may have an association with neuronal plasticity and re-establishment of neuronal network post DAI. |
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