As the study finding new evidence; that a protein pumped out of some but not all populations of “helper” cells in the brain, called astrocytes; playing a specific role in directing the formation of connections among neurons needed for learning and forming new memories. The role of astroglia in regulating neuronal function; little is knowing about the regional or functional subgroups of brain astroglia and how they may interact with neurons
But by using mice genetically engineered and bred with fewer such connections; the researchers conducting proof of concept experiments; that show they could deliver corrective proteins via nanoparticles to replace the missing protein needed for road repairs on the defective neural highway. But some connective networks are lost or damaged by neurodegenerative diseases such as Alzheimer’s or certain types of intellectual disability, such as Norrie disease; the researchers saying their findings advance efforts to regrow; and repair the networks and potentially restore normal brain function.
Astroglia regulating neuronal function
However, these astroglia are enriching in mouse cortical layer V; expressing distinct molecular markers, including Norrin and leucine-rich repeat-containing G-protein-coupled receptor 6 (LGR6); with corresponding layer-specific neuronal ligands; are finding in the human cortex; and modulate neuronal activity. Astrocytic Norrin appears to regulate dendrites and spines; its loss, as occurring in Norrie disease, contributes to cortical dendritic spine loss.
Although astrocytes appear to all look alike in the brain, we had an inkling that they might have specialized roles in the brain due to regional differences in the brain’s function and because of observed changes in certain diseases. But the hope is that learning to harness the individual differences in these distinct populations of astrocytes may allow us to direct brain development or even reverse the effects of certain brain conditions, and our current studies have advanced that hope.
Particular astrocyte protein
But study on a particular astrocyte protein, glutamate transporter-1; which previous study suggesting was lost from astrocytes in certain parts of brains with neurodegenerative diseases. Like a biological vacuum cleaner; the protein normally sucks up the chemical messenger glutamate from the spaces between neurons after a message is sent to another cell; a step required to end the transmission and prevent toxic levels of glutamate from building up.
But taking the DNA code for Norrin plus the 8,300 “location” DNA; and assembling them into deliverable nanoparticles. When they injecting the Norrin nanoparticles into the brains of mice engineered without Norrin; the neurons in these mice began to quickly grow many more branches; a process suggesting repair to neural networks. They repeated these experiments with human neurons too.