Acute Changes Of Facial Nucleus Pathologicle And Expressions Of Postsynaptic Density Protein 95 Following Facial Nerve Injury Of Different Extent: Semi-Quantitative Analysis

Background It was proved postsynaptic density protein 95(PSD-95) widespread in central nervous system,and was related to the development of the central nervous system and sensory signal transmission and kinds of either acute or chronic cell death following ischemic brain injury.More and more researches have found visible changes of the expression of PSD-95 in a lot of nervous system disorders.For this reason scholars tried to explore the relationship between PSD-95 and peripheral nerve system,in order to find a new therapic target for peripheral nerve lesion.Objective To semi-quantitatively observe the pathological change of apoptosis facial neuron by HE staining method,and the expression of PSD-95 in facial nucleus following facial nerve injury of different extents by immunohistochemical staining method as well.Design time and locality Random contrast animal experiment,was completed in Ultrasonic Institute of the Second Affiliated Hospital of Chongqing University of Medical Sciences during September and December in 2007.The treatments to rats during the experiment were all consistent with animal ethical standards.Materials Healthy common adult SD rats were adopted,either male or female,added 3 monthes,with body mass of 180 to 230 g,provided by the Animal Center of Chongqing University of Medical Sciences.All the rats were fed ordinary grana forage in mono-cage respectively.Rabbit anti-rat PSD-95 polyclonal antibody was bought from Beijing Biosynthesis Biotechnology Co.,LTD.SP-9001 rabbit anti SP immunohistochemical reagent kit and DAB reagent kit were bought from Beijing Zhongshan Goldenbridge Biotechnology Co.,LTD.METHODS Totally 65 adult SD rats were randomized into a control group(five rats) and three injured groups(20 rats per group),which were damaged at three different extents of exposure clamp and cut.The post-three groups were observed on the 1st,3rd,7th and 14th days after injury,with 5 rats at each time point.The control group was given none treatment.CHIEF OBSERVATION INDEX The brainstems were taken on the 1st,3rd,7th and 14th days after injury.Apply Hematoxylin-Eosin (HE) staining to facial nucleus dyeing to observe the pathological change of apoptosis facial neuron.And count the amount of the PSD-95 positive cells immunohistochemically stained by PSD-95 polyclonal antibody under light microscope.RESULTSâ‘ The expression of PSD-95 in facial nucleus and appearance of facial neuron in the exposure group had no obvious change at different time point(P>0.05).But the expressions of PSD-95 in facial nucleus of the clamp group and cut group had been increased at one day after injury(P<0.05),and obviously again at seven days(P<0.01),but had not seem to be dropped at fourteen days;Facial neuron had appeared apoptosis change on the 3rd day,and even more obvious on the 7th day,but had not seem to be refectious on the 14th day.â‘¡When compared between different groups,the amount of the positive cells in facial nucleus stained by PSD-95 polyclonal antibody and the apoptosis extent of facial neuron at the same time point after injury were that cut group>clamp group>exposure group.CONCLUSIONS The apoptosis extent of facial neuron were raised with the aggravation of injured severity of facial nerve,and which was the same with that of the expression of PSD-95 in apoptosis facial neuron.