Histogenesis Of Neuroimmune In Mouse Retina

Neuroimmune plays a very important role in the human body,which mainly includes immune cells(such as microglia cell,macrophages,dendritic cells,etc.),cytokines(such as interleukins,vascular endothelial growth factor and tumor necrosis factor,etc.)and immune barrier(such as the blood brain barrier,the blood retinal barrier,etc.).As a part of the central nervous system,the retina has immune system as well.In retina,there are a number of neurons and glial cells.In the central nervous system,microglia is a kind of very important glial cells,and is also a special kind of mononuclear phagocyte.It can remove damaged cells,plaque,nerves,or infectious material of the central nervous system.In the central nervous system,microglia is an important and indispensable component,and also is to resist pathogens for the first line of defense.In addition in the retina,with vascular endothelial cells,basement membrane and perithelial cells,astrocytes,constitute the blood retinal barrier.Unlike immune cells,blood retinal barrier is a kind of natural immune barrier.It can block some bacteria or molecular material into the eyes,making retina own high immunity.If the blood retinal barrier is damaged,the retina will appear edema,and can quickly lead to retinal function damage so that visual function obstacle,which serious still can cause blindness.Therefore,microglia and blood retinal barrier of retinal neural immune system,have a certain ability to resist infection,and can effective resistance to pathogen infection.Objective: We tried to investigate the histogenesis of neuroimmune system,such as microglia and blood retinal barrier,in mouse retina.Methods: The detachment and stretched slice of mouse-retina,frozen section,immunohistochemistry,DiI diotistic assays,gelatin-ink perfusion,transmission electron microscopy(TEM)and statistical analysis were used to visualize the structures of retinal microglia and blood retinal barrier with Kunming mice at E10?E14?E16?P0?P1?P3?P5?P7?P9?P10?P14?P21?P30?P60?P90?P180(n=5~10)(E: embryonic day,P: postnatal day).Results:(1)At as early as E10,the microglia could be found to distribute over retina evenly.With development,the microglia changed from amoeba-like shape to star-like shape with many processes.The number of microglia increased after the birth and reached their plateau at P5,then the number of cells went down.(2)After birth,the retinal vasculature developed from the optic disk,and grew out to entire retina at P10.As age increasing,the volume density of vasculature was declined down,but the number of blood capillary thoroughfare channel increased.(3)The blood retinal barriers appeared as early as at P0.At P30,they became mature,consisting of endothelial cell,basal membrane,pericyte and the terminal feet of astrocytes.Conclusion:(1)As retinal development,microglia became more and more mature,their number changed from few to reduce again,with parabolic model,the largest when the P5.(2)With development,the volume density of vasculature was declined down,but the number of thoroughfare channel increased.(3)At P30,the blood retinal barrier had been developed maturely in structure with endothelial cell,basal membrane,pericyte and the terminal feet of astrocytes.(4)The microglia and blood retinal barrier were involved in anti-infection and resistance to various pathogens.