Cell: Small glial cells give way to space for new synaptic formations by devouring extracellular matrixes.

!--:page title"--July 12, 2020 // --- In order to create new memories, our brain cells must first find each othersmall protrusions protruding from the endof of the neurons' long branches of tentacles to connect them together so that they can talkthe ports of these cells chat, known as synapses, have found trillions of synapses throughout the brain, allowing us to present new knowledge, however, scientists are still learning how these connections respond to new experiences and informationNow, in a new study, researchers at the University of California, San Francisco, have discovered a new way for brain immune cells to help solve problemsrelated findings were published online July 1, 2020 in the journal Cell, with the title "Microglial Remodeling of the Extracellular Matrix Synapse Plasticity."picture from Cell, 2020, doi: 10.1016/j.cell.2020.05.050in recent years, scientists have found that specialized immune cells in the brain, called small glial cells, can help remove unnecessary connections between neurons, possibly by swallowing synapses and breaking them down, however, the new study found that small glial cells can do the opposite--- by swallowing dense protein mesh structures between cells to make way for new synapses, so neurons have room to find each otherthe researchers say that continuing to study this new role in small glial cells may eventually lead to new therapeutic targets for some memory disordersneurons live in a gel-like mesh structure made up of proteins and other molecules, helping to maintain the three-dimensional structure of the brainthis stent, collectively known as the extracellular matrix (ECM), has long been overlooked in neurosciencefor decades, scientists have focused on neurons, and more recently, cells that support neurons, and they largely believe that extracellular matrix estoctics are not important, however, neurobiologists are beginning to realize that extracellular matrixes, which make up about 20 percent of the brain, actually play a role in important processes such as learning and memory, for example, at some stage of brain development, cured extracellular matrix seems to brake on the rapid turnaround rate of new neurons connected in infants, seemingly shifting the brain's priorities from adapting to the new world around them to maintaining more stable knowledgescientists also want to know whether the rigidity of the extracellular matrix in later life may somehow address the memory challenges of aging"The extracellular matrix has always been there," said Phi Nguyen, a biomedical science researcher at the University of California, San Francisco, the first author of the paper But it has certainly not been fully studied " Nguyen and his mentor, Dr Anna Molofsky, an associate professor in the Department of Psychiatry and Behavioral Sciences at the University of California, San Francisco, first realized for the first time that extracellular matrix was important for their research on the hippocampus, a brain structure critical to learning and memory , knowing that small glial cells can devour outdated synapses, they expect that destroying the function of small glial cells will lead to an increase in the number of synapses in the hippocampus the opposite, the number of synapses has fallen where they thought they would find fragments of synapses broken down in the "belly" of small glial cells, they found fragments of extracellular matrix "In this case, small glial cells devour something different than we expected," Molofsky said they are in the space around the synapses, clearing obstacles to help new synapses form the study found that before starting action, small glial cells wait for signals from neurons, an immune molecule called IL-33, that indicates the time to form new synapses when the researchers used genetic tools to block the signal, small glial cells failed to perform their duties on extracellular matrix, which led to fewer new connections between neurons in the mouse brain and made it difficult for mice to remember certain details for a while when they increase the level of the IL-33 signal, the number of new synapses increases in older mice, brain aging has slowed the formation of new connections, and increasing IL-33 levels helps push the number of new synapses to younger levels According to co-author Dr Mazen Kheirbek, an associate professor of psychiatry at the University of California, San Francisco, the study may be important to understand that --- may one day treat --- the memory problems we see in age-related diseases such as Alzheimer's disease However, these findings may also be important for specific types of emotional memory problems that are sometimes seen in anxiety-related diseases To determine how changes in IL-33 affect memory, the researchers taught mice to distinguish between anxiety-induced boxes (in which mice received a slight foot shock) and neutral boxes a month later, normal mice expressed more fear in the anxiety-inducing box by staying in place (a rodent that flung off the predator's reflexes) much more than they did in a neutral box, and they moved more casually in the neutral box but the mice that were destroyed by IL-33 expressed high levels of fear in any box, suggesting that they had lost the precise memory of determining when to be afraid and when it was safe Kheirbek likened the over-the-dosing reaction to the fear of trauma that could result from being robbed in a parking lot at night some people may develop a generalized fear that makes it difficult for them to enter any parking lot at any time, without being able to separate the memory of that fear from new, perhaps less frightening, experiences "In many anxiety disorders, especially in post-traumatic stress disorder (PTSD), this very precise impairment of emotional memory ability can be observed," said It's an over-generalized fear that really interferes with your life ", in Molofsky's case, the accidental discovery of this unexpected result made her eager to learn more about the extracellular matrix and how it shaped the way we learned her lab is now working to identify new, less distinctive extracellular matrix fragments to find ways in which it interacts with neurons and small glial cells in the brain that have not yet been recorded "I'm obsessed with extracellular matrix," says !--/eweb !--editor." many people don't realize that the brain is not just made up of nerve cells, but also the cells that keep the brain healthy, and even the space between cells is full of fascinating interactions I think a lot of new ways of treating brain disease come from memory " (bioon.com) References: 1.Phi T Nguyen et al Microglial Remodeling of the Extracellular Matrix Promotes Synapse Plasticity Cell, 2020, doi:10.1016/j.cell.2020.05.05.05.2.To neuron lettalk, immune cells cells que s trus s