| Amira is a3D data visualization, analysis and modeling software. Itallows you to visualize scientific data sets from various application areas, e.g.medicine, biology, bio-chemistry, microscopy, biomed, bioengineering.3Ddata can be quickly explored, analyzed, compared and quantified. Amira is asoftware platform for visualizing, manipulating, and understanding LifeScience and bio-medical data coming from all types of sources and modalities.The visualization and analysis capabilities of amira in all visualization andsimulation fields in Life Science make it gradually become an important toolin research of Life Science field.The dendritic spines which are the sites of formation of synapse are thefunctional structure of axospinous synapses dendrites and are sites of synapticinput. They involve in signal transduction of over90%excitatory synapse.Structure determines function, the morphology keeping changing and affectedby many factors and function of the dendritic spines are inseparable. Theirchanges are consistent with the changes of the synapse structure that are toadapt to the alteration of external environment, and are closely related tolearning and memory function of the brain and some diseases of Neurologyand Psychiatry. The postsynaptic density is the fiber specialized area on thecytoskeleton of postsynaptic membrane. It is a massive multi-protein complexwhose functions include many aspects such as regulation of cell adhesion,control of receptors recruitment, regulation of receptors’ functions, especiallypositioning signaling molecules for induction of long-term potentiation anddepression of synaptic strength which are thought to underlie learning andmemory formation. There are many signaling molecules in the PSDs, they canregulate the synaptic plasticity and morphology of dendritic spine by cross-linking pathway. Many PSD proteins are related to diseases ofNeurology and Psychiatry. Given that dendritic spine and PSD both affectsynaptic plasticity, and their spatial position is very close, many academicssuppose that there may be some kind of relation between them to keepsynaptic efficacy steady.According to integrity of PSD, the excitatory synapse can be divided intoperforated synapse and non-perforated synapse. Through many studies ofperforated synapse, yet the majority of researchers think that perforatedsynapsis are important through the processes of development of synapse andsynaptic plasticity. Under many pathology conditions, the radio of perforatedsynapse to all synapse changes.Fragile X syndrome is one of the most common forms of inherited mentalretardation, with a frequency of1in4000men and1in8000females. It isassociated with a CGG repeat expansion in the5’-untranslated region of theFMR-1gene.FMR-1knock-out mouse is a kind of model of FRX mouse andhas many characteristics of FRX patients. There is a spatial learning memorydisorder existing in FMR-1knockout mice suggest that there may beparamorphia in axospinous synapses and their dendritics in hippocampuspyramidal cells.International and domestic academics using amira have reconstructed theliver and basal ganglia. But amira’s application in the field of ultrastructure isvery little. The observation of ultrastructure is benefit for diagnosis of somenervous system diseases and exploration of pathogenesis.Objective：This experiment establishes the3-D structures of the dendritic spine andpostsynaptic density of axospinous synapse of hippocampus CA1area of miceby AMIRA in normal mice and FMR-1knockout mice, and surveys their3-Dstructures. This experiment can show intact PSD by3-D reconstruction whichcan clearly distinguish perforated synapse and non-perforated synapse. We cancalculate the proportion of perforated synapse in total synapses in normal miceand FMR-1knockout mice. We can directly measure the volume of dendritic spine head and PSD in normal mice and FMR-1knockout mice to confirm therelationship between dendritic spine head and PSD in normal mice and thechange of dendritic spine head and PSD in FMR-1knockout mice from theview of3D angle. All this results demonstrate that as a image analysissoftware, amira can conveniently explore nerve anatomy pathologicalmechanism of some nervous system diseases, and will provide potentassistance for stereo diagnoses of clinical medicine.Methods:The prepared brain tissue is sliced and photographed in transmissionelectron microscope (TEM) by using Ultra-thin technology of serial section.We collect several serial images of normal mice（control group） and FMR-1knockout mice（experimental group）. Then we use photoshop, ImageJ,AMIRA software to dispose and analyze the images to get the data we need.Then we use SPSS13.0statistical software to analyze the data to get relativitybetween the data.Results:1After aligning and cropping by photoshop and ImageJ, we can get theserial images of single-dendritic spine-PSD. By using AMIRA, we cangain the3-D structure of dendritic spine-PSD of normal mice and FMR-1knockout mice.2We can distinguish perforated synapse and non-perforated synapse from3-D image.5of48groups of serial images in control group belong toperforated synapse demonstrate that the proportion of perforated synapseof total synapses is10.4%.14of48groups of serial images in FMR-1experimental group, the proportion is29.2%（χ~2=5.315，P＜0.05）.3We acquire the volume amount of the dendritic spines head and PSD andthe radio between them measuring by AMIRA. The result of statisticanalysis by SPSS13.0shows that in control group, the average of volumeamount of dendritic spines head is700164.21±115532.87,and the averageof volume amount of PSD is69286.90±11446.60.There is a positivecorrelation between dendritic spine head and PSD in control group, correlation index is0.994, P＜0.01,the result has statistical significance.Their linear regression coefficient is10.055±0.261.In experimental group,the average of volume amount of dendritic spines head is843540.44±56256.998, and the average of volume amount of PSD is68353.98±4682.047.Theis is still a positive correlation between dendriticspine head and PSD in experimental group, correlation index is0.959, P＜0.01,the result has statistical significance. Their linear regressioncoefficient is11.524±1.010.Conclusion:1We can obtain the3-D structure of the dendritic spine-PSD by usingAMIRA after the disposing of photoshop and ImageJ. We can clearly seethe spatial position of dendritic spine and PSD, and execute360degreerotating of the3-D structure in AMIRA to achieve more information.2Through the analysis of amira the result can clearly shows that there is apositive correlation between dendritic spine head and PSD and comparedto normal mice, and clearly sees the3-D structure of this two kind ofsynapses in3-D reconstruction images. The proportion of perforatedsynapse in KO mice is higher than in normal mice. The volume of spinehead in KO mice is larger than in normal mice.3Amira can provide more experimental evidences for3-D diagnosis ofclinical medicine. |
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