Mild Hypoxic Stress And Neuroglobin Expression In Mouse Central Nervous System

Neuroglobin is an oxygen-carrying globulin with six-coordinated structure,which is mainly expressed in the nervous system of vertebrates.The brain is the largest organ to oxygen demand,which is more sensitive in the nervous system,so the earliest emergent symptom is neurological manifestation under insufficient oxygen supply.Therefore,the study of the distribution and expression of neuroglobin in the brain have great significance to the development of the nervous system and the treatment of its diseases.Researchers have focused on the expression of neuroglobin in the brain or other organs of adult individuals,whereas the distribution of neuroglobin during brain cortex development and expression of the neuroglobin under mild hypoxia stress state were rarely reported.In this study,Kunming mice were used as the experimental model to analyze the expression of neuroglobin positive cells during brain cortex development and under mild hypoxia stress,helping to further understand the role of neuroglobin in the development of the nervous system and providing a more promising basis for treating neurological diseases.Objective: To investigate the expression of neuroglobin in mouse neocortex development process and under mild hypoxia stress.Methods: Collecting the brain of Kunming mice from E16 to p360 were totally 126 cases.Immunofluorescence technique was used to detect the expression of neuroglobin in the process of neocortical development and under mild hypoxia stress.Results:(1)Neuroglobin is expressed in the cytoplasm of the neural stem cells in the subven-tricular zone of brain neocortex at embryonic day 16.The proportion of Neuroglobin positive neural stem cells were gradually reduced in the process of up-migration of the new cortex from ependymal layer.At P30,the expression of neuroglobin in brain cortex was nearly negative.During the development of neocortex,the neuroglobin was expressed in all the cytoplasm of neocortical neurons from E16 to P360.Difference significance test was made to analyze the number of neuroglobin-positive neurons in the unit area at different ages.In the neocortex ?-? layers,the density of neuroglobin-positive neurons was the highest at P1 and then decreased gradually,moreover,the decreased trend kept gradually stable after P14.Interestingly,the neuroglobin-positive neurons was basically same situation in neocortex ?-? layers.In the process of new cortical lamellar development,the positive expression of neuroglobin in the cytoplasm of migratory neurons was weakened;After birth,the number of neuroglobin positive neurons per unit area in the cerebral cortex ?-? layers decreased compared with embryo period.(2)At P120,via swimming exercise of artificial intervention under mild hypoxia condition,the number of neuroglobin positive neurons per unit area in the cerebral cortex ?-?and ?-? layers increased in mild hypoxia stress group compared with the control group.Conclusion:(1)Neuroglobin may be involved in the oxygen supply process of develop-ment of the cortex and neuroglobin positive cells migration.(2)The number of positive expression of neurons increases in physiologically development in the process of relative mild hypoxia condition and neuroglobin may be consumed after birth.(3)Under the condition of exercise mild hypoxia stress,the number of neuroglobin positive neurons expressed is increased and the neuroglobin may be involved in the process of protecting neurons against further damage caused by the lack of oxygen supply.