We know that the bodys immune system is important for keeping everything in check and protecting us. But a lot of us dont realise that the brain also has an immune system.
Microglia, which are the brains immune system cells, are involved in everything from brain development to protecting against diseases such as meningitis and Alzheimers. But for all the good these cells do for us, under the wrong conditions they can also cause us harm.
Microglia belong to a group of non-neuronal cells called glia, which originally were thought to play a supportive role for the brains neurons. Now research shows that microglia actually do much more than only support the neurons: they nourish, protect and sometimes even destroy them.
These cells are unique because they come from the same place as other immune system cells, but have a different origin from other brain cells, which develop from neural stem cells. Microglia come from the yolk sac an extra embryonic membrane and travel to the brain early during its development.
Once established, microglia perform numerous functions. They help neurons connect, clean the brain of waste and dead or injured cells, constantly check everything is in order, and defend the brain from external threats (such as microbes), and internal threats including misfolded proteins (when a protein takes on the wrong form, which can cause disease). Their ability to change physical form and behaviour in response to their environment allows them to perform these many roles.
Microglial functions are especially crucial during brain development, when they help young neurons grow, and ensure the right connections are made between neurons. Through a procedure called pruning, microglia eat connections between neurons, maintaining strong ones while eliminating weaker or unnecessary ones. This continues somewhat during adulthood. For example, microglia remove unimportant memories by eating or altering synapses involved in their maintenance.
Faulty pruning during brain development has been linked with disorders such as schizophrenia and autism. But uncontrollable pruning by microglia in adulthood has been implicated in developing diseases such as Alzheimers.
Microglia have specific receptors on their surface which recognise distress signals from other cells. These signals attract microglia to the site of the problem. When the brains balance is disturbed (usually as a result of inflammation), living neurons can become stressed and produce these signals. This may cause them to be eaten alive by microglia. As neurons are killed, the connections they have with other neurons are also eliminated, which can cause severe issues in brain connectivity and functions.
Inflammation in the brain can be caused by stress, pathogens, and auto-immune conditions, and is also connected to inflammation in other parts of the body. Brain inflammation is common in neurodegenerative diseases, as well as mental health disorders, including depression.
Inflammation causes microglia to change roles, and turn into their aggressive form to defend the brain. Usually, when stress signals stop and anti-inflammatory signals are received, microglia go back to first repairing, then protecting the brain.
But there are cases, such as with chronic stress, ageing and neurodegenerative disorders, where microglia can become more aggressive and less easy to regulate, making them more dangerous for the brain. In these cases, microglia can increase in numbers, unnecessarily kill nearby cells, and may contribute to making the brain even more inflamed by secreting inflammatory molecules. They also dont go back to their protective role easily.
But there are many things we can do to keep our microglia happy and our brains healthy such as:
Maintain a healthy diet: Compounds found in fruits, vegetables, and healthy fats, can keep your microglia young, and shift them towards an anti-inflammatory form.
Keep your gut bacteria happy: The brain and the gut are connected by the vagus nerve, so microbes living in our gut have a large effect on the brain. These microorganisms are involved in the development, maintenance, and overall health of microglia.
Avoid alcohol and smoking: Alcohol causes brain damage. A recent study found that one of the ways it does so is by activating the microglias inflammatory response. Research shows this activation is also induced by a specific compound found in cigarette smoke.
Sleep: Microglia never sleep, but they clean and repair the brain and improve memory while you do. Lack of sleep, however, has also been shown to make microglia take on their inflammatory form.
Take care of your mental health: Microglia can sense stress, and they respond to it by turning into their inflammatory form. This form is present in numerous neuropsychiatric disorders, and also in some cases mental health issues (such as depression) that precede neurodegenerative disorders.
It has also been shown that anti-inflammatory treatment can help with managing the symptoms of psychiatric disorders, and that some medications used for the treatment of mental health issues have an anti-inflammatory element. Antidepressants have also been shown to directly regulate microglia responses.
Exercise: A recent review found exercise directly affects microglia, and shifts them towards having a protective form. Exercising the brain has also been shown to train microglia to resist Alzheimers disease.
Although we know some things about microglia, we dont know everything. We know some things about how they form, that theyre involved in many diseases, and that they might essentially control the brain. But we also know we cant control them. Future research might focus on how we can stop microglia from causing diseases, and how to stop these cells from turning against the brain.
- Overview of the Immune System - The Merck Manuals - March 18th, 2024
- SUNDAY Unraveling The Gut-Brain Connection: How Infant Gut Bacteria Shape Immune Resilience | TheHealthSit - TheHealthSite - March 18th, 2024
- Making drugs from T cells: The quantitative pharmacology of engineered T cell therapeutics | npj Systems Biology and ... - Nature.com - March 18th, 2024
- Study unlocks the mystery of neonatal neutropenia in newborns - News-Medical.Net - March 18th, 2024
- Vertebral Subluxation and Systems Biology: An Integrative Review Exploring the Salutogenic Influence of Chiropractic ... - Cureus - March 18th, 2024
- A new strategy to attack aggressive brain cancer shrank tumors in two early tests - ABC News - March 18th, 2024
- Turning on the Bat Signal - The Scientist - March 18th, 2024
- Power Foods That Can Support Your Immune System - Videos from The Weather Channel - The Weather Channel - March 18th, 2024
- Report: Aggressive brain tumors respond to new, immune-focused therapy - UPI News - March 18th, 2024
- Designer immune-cell therapy could shrink deadly brain tumors, early trials show - Livescience.com - March 18th, 2024
- 20.2: Introduction to the Immune System - Biology LibreTexts - February 27th, 2024
- Can one shot of yoghurt really boost your immunity and gut health? - Daily Mail - February 27th, 2024
- New cancer therapy approved by FDA supercharges bodys immune system - The Washington Post - February 27th, 2024
- How bubonic plague rewired the human immune system - BBC.com - February 27th, 2024
- Innovative therapy targets and destroys leukemia stem cells - News-Medical.Net - February 27th, 2024
- Participate in Our Study for $100; Open Slots This Week - University of Arkansas Newswire - February 27th, 2024
- Sexual dimorphism during integrative endocrine and immune responses to ionizing radiation in mice | Scientific Reports - Nature.com - February 27th, 2024
- Comprehensive pan-cancer analysis identifies the RNA-binding protein LRPPRC as a novel prognostic and immune ... - ScienceDirect.com - February 27th, 2024
- YOUR HEALTH: The HAMR fights cancer - WAFB - February 27th, 2024
- Cycles of a diet that mimics fasting can reduce signs of immune system aging, as well as insulin resistance and liver fat - News-Medical.Net - February 27th, 2024
- How the powerhouse of the cell could be cancers Achilles heel - Freethink - February 27th, 2024
- Food is medicine: The science behind zinc and other supplements for immune health - Healio - February 27th, 2024
- Unleashing Our Immune Response to Quash Cancer - Medscape - February 27th, 2024
- Tumor histoculture captures the dynamic interactions between tumor and immune components in response to anti-PD1 ... - Nature.com - February 27th, 2024
- Converging and evolving immuno-genomic routes toward immune escape in breast cancer - Nature.com - February 27th, 2024
- Sanjula Jain Urges a Comprehensive Approach in Address Alarming Rise in Cancer Cases Among Younger Populations - Managed Healthcare Executive - February 27th, 2024
- Cystic fibrosis breakthrough points to zinc as infection buster - New Atlas - February 27th, 2024
- Exploring synergies between B- and T-cell vaccine approaches to optimize immune responses against HIVworkshop ... - Nature.com - February 27th, 2024
- Is the 100-year old TB vaccine a new weapon against Alzheimers? - The Guardian - February 27th, 2024
- Immune system in the blood of Alzheimer's patients found to be epigenetically altered - News-Medical.Net - February 10th, 2024
- What impact does exercise have on your immune system? And how to stay well while cycling - BikeRadar - February 10th, 2024
- Had COVID recently? Here's what to know about how long immunity lasts, long COVID, and more - AAMC - February 10th, 2024
- Noor Momin harnesses the immune system to treat heart disease | Penn Today - Penn Today - February 10th, 2024
- Research reveals a process tumors use to induce immune suppressor cells and evade immunotherapy - Medical Xpress - February 10th, 2024
- Immune targeting of HIV-1 reservoir cells: a path to elimination strategies and cure - Nature.com - February 10th, 2024
- Preventing severe allergic reactions with nanoparticles - National Institutes of Health (NIH) (.gov) - February 10th, 2024
- Sugary handshakes are how cells talk to each other understanding these name tags can clarify how the immune ... - The Conversation Indonesia - February 10th, 2024
- Scientists have identified an immune cell that can cause allergies - EL PAS USA - February 10th, 2024
- Sickle cell and the importance of the immune system - Punch Newspapers - February 10th, 2024
- Which cancers can be treated with immune checkpoint inhibitors? - MD Anderson Cancer Center - February 10th, 2024
- How does waste leave the brain? Washington University School of Medicine in St. Louis - Washington University School of Medicine in St. Louis - February 10th, 2024
- Healthy Kids: Give your immune system a boost to stay healthy this winter - nbc16.com - February 10th, 2024
- The impact of prior exposure to hypoglycaemia on the inflammatory response to a subsequent hypoglycaemic episode ... - Cardiovascular Diabetology - February 10th, 2024
- Impact of Chronic Stress on Immune System and Depression | Health News - Medriva - February 10th, 2024
- I tried 'swamp soup,' the viral recipe that promises to boost your immune system - Yahoo News - February 10th, 2024
- Understanding Immune Checkpoint Inhibition Therapy: Challenges and Strategies - Medriva - February 10th, 2024
- One Simple Change May Dramatically Boost The Effect of COVID-19 Vaccines - ScienceAlert - February 10th, 2024
- The gut virome is associated with stress-induced changes in behaviour and immune responses in mice - Nature.com - February 10th, 2024
- Cancer vaccines are in the works to fight BRCA-linked gene mutations - The Philadelphia Inquirer - February 10th, 2024
- What are the organs of the immune system? - InformedHealth.org - NCBI ... - January 17th, 2024
- Novel insights into the immune response to bacterial T cell superantigens - Nature.com - January 17th, 2024
- FDA signs off on Takeda's HyQvia as maintenance therapy for CIDP - FiercePharma - January 17th, 2024
- CBDs Pobezinsky and Pobezinskaya Use Flow Cytometry to Determine How Tumor Cells Outwit the Bodys Immune ... - UMass News and Media Relations - January 17th, 2024
- Boosting. What To Do. - Science Based Medicine - January 17th, 2024
- Axelia Oncology takes its TLR2/6 agonist into the clinic to harness the innate immune system - BioWorld Online - January 17th, 2024
- Long COVID manifests with T cell dysregulation, inflammation and an uncoordinated adaptive immune response to ... - Nature.com - January 17th, 2024
- Opinion | Thanks to mRNA, Future Drugs Will Be Easier and Faster to Make - Mississippi Free Press - January 17th, 2024
- Elon research team models the COVID immune response, one equation at a time - Today at Elon - January 17th, 2024
- Are plant-based meals good for your immune system? 4 things to know about improving your health this week. - Yahoo Life - January 17th, 2024
- Scientists Find Key To Potential Breast Cancer Prevention, Treatment | Newsroom - UNC Health and UNC School of Medicine - January 17th, 2024
- What if every germ hit you at the exact same time? An immunologist explains - The Conversation - January 17th, 2024
- Why Don't We Have a Staph Vaccine? - Healthnews.com - January 17th, 2024
- Best ways to improve your immune system - The Business Standard - January 17th, 2024
- Stanford University researchers think future pandemics could be prevented with universal vaccines - KGO-TV - January 17th, 2024
- Why you may feel depressed and anxious when you're ill and how to cope with it - The Conversation - January 17th, 2024
- New mechanism with potential to boost checkpoint-blocking cancer immunotherapies identified - Medical Xpress - January 17th, 2024
- Battling Bugs and Blues: The Interplay of Infection and Emotion - News-Medical.Net - January 17th, 2024
- What if every germ hit you at the exact same time? - RTE.ie - January 17th, 2024
- Evolutionary conservation of CD4 and LAG-3 and their cytoplasmic tail motifs with opposing immune functions - Medical Xpress - January 17th, 2024
- Probiotics and yogurt vs. depression ... and the winner is? - The Union Leader - December 30th, 2023
- Which Vitamins Boost The Immune System? - MSN - December 30th, 2023
- Opinion | We Need a Global Immune System to Stop Future Public Health Crises - The New York Times - December 30th, 2023
- Understanding the Immune System and How to Support It | Health News - Medriva - December 30th, 2023
- Seven of the biggest medical breakthroughs in 2023 | South Central Illinois' News, Sports and Weather Station - WJBD News - Salem, Illinois - December 30th, 2023
- Understanding the Dynamics of Innate Immune System in SARS-CoV-2 Infection and Its Potential for Treatment - Medriva - December 30th, 2023
- Resolvins: Firefighters In The Battle Against Chronic Inflammation - Forbes - December 30th, 2023
- Does Taking Vitamin D Supplements Reduce Severity Of COVID-19? - MSN - December 30th, 2023
- Study Reveals Variations in CNS-Associated Macrophages: Implications for Aging and Disease - Medriva - December 30th, 2023
- What are the benefits of zinc and when should you take supplements? - HOLA! USA - December 30th, 2023
- Elle's immune system is so severely compromised she has to live in a bubble with her 'bubble mummy' - ABC News - December 22nd, 2023