Immune Cells repair brain and spinal cord while sleeping: Research

Immune cells called microglia are primarily active while sleeping, as suggested by the study's lead author Ania Majewska, Professor at the University of Rochester in the US. Microglia play an important role in reorganizing the connections between nerve cells, fighting infections and repairing the damage. They also serve as the brain's first responders, patrolling the brain and spinal cord and springing into action to stump out infections or remove the debris from dead cell tissue. 

On the official page of the Univerity, Professor Majewska said, “This research shows that the signals in our brain that modulate the sleep and awake state also act as a switch that turns the immune system off and on. It has largely been assumed that the dynamic movement of microglial processes is not sensitive to the behavioral state of the animal” 

READ: Indian Scientist Develops Low-cost, High-res Satellite Imaging System

READ: 'Novel Catalyst Can Help Turn Carbon Dioxide Into Fuel' 

Role of norepinephrine

According to previous studies, microglia interact with synapses, the juncture where the axons of one neuron connect and communicates with its neighbours. The microglia help maintain the health and function of the synapses and prune connections between nerve cells when they are no longer necessary. The current study, on the other hand, points to the role of norepinephrine, a neurotransmitter that signals arousal and stress in the central nervous system. The study showed that norepinephrine acts on a specific receptor, which is at high levels in microglia. 

This work suggests that the enhanced remodeling of neural circuits and repair of lesions during sleep may be mediated in part by the ability of microglia to dynamically interact with the brain,” said Rianne Stowell, Ph.D. a postdoctoral associate at URMC and first author of the paper. “Altogether, this research also shows that microglia are exquisitely sensitive to signals that modulate brain function and that microglial dynamics and functions are modulated by the behavioral state of the animal.” 

READ: NASA Posts Hubble Space Telescope's Beautiful Image Of Galaxy NGC 4380

READ: Compound Effective Against Chemotherapy-resistant Cancer Invented

READ: NASA's InSight Starts Digging Into Mars Again, After Burying Itself