Immunohistochemistry, using the basic principles of immunology - the antigen-antibody reaction, namely antigen and antibody specific binding principle, by chemical reaction of the labeled antibody reagent (luciferase, an enzyme, metal ions, isotopes) to confirm the antigens (peptides and proteins) in tissues, its location, qualitative and quantitative research, called immunohistochemistry (immunohistochemistry) or immunocytochemistry techniques (immunocytochemistry).It combined the specific of immune response with visibility of histochemistry by means of a microscope (including fluorescence microscopy, electron microscopy) imaging and amplification, detection of various antigens in a cell, subcellular level, such as proteins, polypeptides, enzymes, hormones, pathogens, and receptors. Immunohistochemical techniques have developed rapidly in recent years. It was limited to immunofluorescence techniques in 1950s, but gradually developed after the 1950s to establish a highly sensitive and more practical immunization enzyme technology.
The brain is the main part of the central nervous system, located within the cranial cavity. The brain of lower vertebrates is relatively simple, but that of human and mammalian brain are particularly well-developed. The brain is the most complex organ in vertebrates, in a typical human cerebral cortex (the largest part), estimated to contain 15-33 one billion neurons,  each connected by synapses to thousands of other neurons. These neurons communicate with each other by a long fiber called axons puree, which carry signal pulses called action potential to target specific recipient cells. The brain is the body's control center. It controls memory, language and sports. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, if problems occur, the results can be disastrous. Immunohistochemistry has been frequently used on human and mouse brain sections for detecting pathologies in the endocytic-autophagic-lysosomal pathways such as changes in the numbers, types and distribution of vacuoles, and expression levels of individual molecules in the pathways.A variety of target molecules expressed on brain tissue is used for the clinical diagnosis of heart disease, brain tissue is commonly used in immunohistochemical detection. IHC is an important means to be widely used to detect brain disease.