Comparative Study on Multiple Concussions Rat’s BB、BW and FS Rehavioral Changes and Brain Tissue GFAP and MBP Changes
|Keywords||MCC BW FSPCC MCC24h MCC72h GFAP MBP|
PART1To Research the Rat’s BB、BW and FS Behavior Changes after Post-triple Concussion[Objective]:To establish the triple concussion rat model, and observe post-concussion beam walking test and forced swimming test behavior changes, and assess the rats’homeostasis movement, the restoration of learning and memorizing, the depression status of mental activity.[Methods]:(1) animal grouping:20healthy SD rats, half male and half female, weighing260±20g, the rats were randomly divided into MCC72h beam walking group and MCC72h forced swimming group, n=10, half male and half female.(2) application of metal pendulum device, strike PCC every72h, strike three times to duplicate MCC72h model.(3) After cerebral concussion within16days, apply BB and BW to evaluate the rats’static and dynamic balance function, motor coordination function and changes of motor learning and memory function; apply FS to the evaluate the MCC72h rats’depression status in the3ed,7th,15th,30th day after brain concussion.[Results]:(1) BB score results:All the rats been experimented can keep their static equilibrium throughout the experiment with results steady in60.00±0.00s.The MCC24h rats appeared different degree of static balance function damage within9days after injury.(2)BW score results:Rat MCC72h model restored to normal after the first day of injury, i.e the score remains in5throughout the experiment. The rats been tested in the noise stimulus can successfully run through the obstacles in the rod and into the cartridge. The MCC24h rats’BW score decreased after the1-2days injury, and the PCC and MCC72h groups were statistically significant, P<0.05, and then back to5(3) the results of BW slip into incubation period:MCC72h group compared with normal group,1-3days after injury are statistically significant. P<0.05. The PCC and MCC72h group’s STL rats after injury throughout the observation time point differences were not statistically significant, P>0.05; The MCC24h and MCC72h group after3-6days injury, the STL difference was statistically significant, P<0.05).(4) BW slip frequency results:the MCC72h rats after injury slip frequency increases, it comes to the peak in the3ed day, then gradually decreased, day8appeared a small peak.[Conclusions]:(1) the PCC and MCC24h MCC72h rats after injury did not see damage change in static balance ability.(2)The dynamic movement of PCC, MCC72h rats balance, movement coordination, learning and memory functions within4days after the last blow appeared short-term abnormal changes, and the corresponding function of MCC24h rats showed obvious injury in8th day after injury.(3) the PCC, MCC24h and MCC72h rats’three different damage types to balance the movement function injury after injury severity for:MCC24h> MCC72h> PCC> normal control group; In depression behavior frequency:MCC72h> MCC24h> PCC> normal control group. PART2Comparative Study on GFAP and MBP Changes in Rats’Brain Tissue after Concussion[Objective]:To establish the model of pure cerebral concussion (PCC) and multiple cerebral concussion(MCC) in rats, with the interval time of triple blow in concussion respectively be24h and72h. Observe and compare the changes of the glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) in the different brain regions and the changes of GFAP and MBP in each day of PCC and MCC, so as to understand the changes of neurohistology after cerebral concussion in rats.[Methods]:(1) Grouping rats:ninety-six healthy SD rats, half male and half female, weight between260±20g.R.andomly divide them into normal group, PCC model group, MCC24h model group, MCC72h model group, and then divide these groups into1-day group,4-day group,8-day group,16-day group and24-day group randomly.(2) Use a metallic pendulum-striker concussive device to reduplicate30rats PCC model,30MCC24h model and30MCC72h model respectively.(3) The GFAP and MBP of the different encephalic region which include septal area section, hippocampus section, brainstem section and so on were stained with anti-GFAP antibody and Anti-MBP antibody using S-P method so as to detect the expression of GFAP and MBP in different brain regions, and then use image analysis system to measure and analysis the above regions’GFAP and MBP positive reactant cell count and light density respectively.[Results]:(1)after PCC, MCC24h and MCC72h model GFAP positive cells counting results:in the PCC, MCC24h, MCC72h model copy, prefrontal cortex coronal section, the hippocampus coronal section and brainstem sagittal cross-sectional areas of the brain, the number of GFAP positive cells in the first day after injury gradually increased, and to the peak in the eighth day after the reduplication. Compared with the normal control group, the diversity of the number of positive cells were statistically significant,(p<0.05);②On the first day after concussion of MCC72h, GFAP positive cells in the copy of the MCC72h model entered to high expression levels, which is higher than MCC24h、PCC and the normal control group;③On the8th day after injury of MCC24h group, the number of GFAP expression reaches its peak, compared to other groups, and it sustained for the longest time;④On the first day after injury, the GFAP expression increased and its difference with normal group is statistically significant(p<0.05). The range of increase and decrease is in minimal.(2) MBP in the PCC, MCC24h and MCC72h positive reactants optical density analysis results:①MBP in the prefrontal cortex coronal section, the hippocampus coronal section and the brainstem sagittal section after the copy of the the PCC, MCC24h, MCC72h model, the optical density value of positive reaction in the first day after injury gradually decreased. On the4th days, it reached to the lowest point, compared with the control group, the physical optical density value differences were statistically significant (p<0.05).②Replication group of MCC72h model into a low expression in the first days after injury, similar to the PCC positive reactant’s optical density, but on the4th day, it became lower than PCC group, the difference between these groups is statistically significant (p<0.05);③MCC24h model replication group’s optical density of positive reactants was in a low expression in early stage, and it reached to the lowest on the4th day. Its differences with other groups were statistically significant, and the low expression lasted for a long time.④Replication group of MCC72h model into a low expression in the first days after injury, similar to the PCC positive reactant’s optical density, but on the4th day, it reached to the lowest, later the positive reactant’s optical density rising rapidly to near normal levels.[Conclusions]:(1) The metal pendulum mechanical hammering device can successfully create a pure and triple concussion rat model.(2) after defeat injury PCC, MCC24h and MCC72h, at the end of the expression of GFAP positive cells count appeared different degree of increase, and are expressed most in8th day after injury, Prompt astrocytes injury severity:MCC24h>MCC72h>PCC>the normal group.(3) After PCC, MCC24h and MCC72h injury, MBP positive reactant optical density value expression decline in vary degrees, to the minimum on4th day after injury, prompt oligodendrocytes MBP injury severity:MCC24h> MCC72h> PCC> normal group.(4) In PCC, MCC24h and MCC72h three injury types, the MCC24h is in the heaviest damage degree, the longest, the most obvious damage accumulation effect.(5) after injury of each group of rats, the express spatial distribution of the GFAP positive cells after injury and MBP positive reactant in different brain regions have the characteristics of diffusibility and the impact and hedge is aggravating.