Nr. 30
🧹 The Brain’s Janitors – and Their Moods
🕰️ London, late evening. The fog clings like cotton wool to the mind, the kettle whistles its disgruntled tune 🫖, and I, Sherlock MS, master detective and neurologist, lean over a fresh file: “Microglia: the brain’s remembering immune system.” Wonderful. Cells that remember things. As if my cortex didn’t already have enough to-do lists. 🧠📋
🔎 Metabolism. When you don’t know whom to suspect – it’s almost always metabolism. ⚙️🍽️
🚨 Case 1: The Overzealous Security Guard (trained immunity)
After a strong wake-up call (infection, stress, sterile riot), microglia switch to glycolysis turbo mode – more sugar, quick energy, short circuits. Result: sirens blare, cytokines stand at attention, next trigger hits faster, louder, longer.
👍 Good when real invaders rage.
👎 Bad when the neighborhood just wants to sleep; then the security guard scratches up the living room furniture.
Takeaway: Useful in acute phases, risky if hypersensitive long-term. ⚖️
🕊️ Case 2: The Chill Peacekeeper (tolerance)
Different streets, different tune: microglia switch to OXPHOS & fatty acid oxidation – less sprint, more endurance. Sirens down, but cleanup & repair up: debris cleared, connections stabilized.
👍 Great for chronic smoldering.
👎 But too much chill → real alarms might get missed.
Takeaway: Calms the neighborhood, but don’t let it fall asleep. 😴🔔
⛽️ Case 3: Fuel Metabolism with Brainpower
When sugar runs low, the crew switches to glutamine. The cell engine purrs, energy flows without constant alarms.
Takeaway: Fine tuning instead of full throttle. 🎚️
🧈➡️🔧 Case 4: The Fat District – Lipid Logistics
Microglia gobble myelin & membrane debris. If cholesterol export runs smoothly, inflammation drops, remyelination gets room to breathe.If it goes awry? Lipid droplet traffic jams, lysosomes grumble, inflammation smolders, phagocytosis falters.
Takeaway: Fat isn’t just fat – balance keeps the neighborhood healthy. ⚖️🧯
📝 The Murder Weapon: A Molecular Notebook
How do microglia “remember”? Metabolism scribbles post-its into chromatin (epigenetic marks). Today alarm genes, tomorrow cleaning crew, the day after neutral.👉 Metabolism → Epigenetics → Behavior.No mystery, just an elegant chain of culprits. 🕵️♂️🧬
📝 What Do I Do With This as a Neurologist?
I read the situation like a city map: Do we need decisiveness now (infection, acute damage)? Then a touch of “training” makes sense: fast defense, short-lived, then calm down. Or do we need rest and repair (chronic inflammation, degeneration)? Then “tolerance” helps: fewer sirens, more garbage collection. And in between? Fine tuning: don’t keep sugar at max, boost OXPHOS, improve lipid logistics, use glutamine pathways – situational, not dogmatic. Cranking everything up at once builds the next misfire.
🫶 Final Word
Microglia are like a security team living in a gym: either running marathons 🏃♂️➡️ or doing burpees until they pass out 🤸♂️. Our job: set the right course; endurance when order is needed; sprint when it burns – and hand over the broom, not just the whistle, in time. 🧹📯
Because in the end, it’s not the volume that counts, but whether the street stays clean, safe, and functional. 🚦🧠
I close the file, the fog sulks away 🌫️➡️🌤️.
Case “Microglia Memory”: open, but the fingerprints shine bright. 🔦🧪