Microglial Synaptic Pruning

During brain development, the brain makes way more synaptic connections than it needs — like building more roads than necessary. Microglia (the brain's immune cells) act as "pruners" — they identify weak or unused connections and engulf/destroy them, "pruning" the brain down to the most efficient wiring. Think of a gardener trimming a hedge to give it the right shape. Why MEF2C loss matters in MHS: With reduced MEF2C, microglia go into overdrive. They prune too aggressively, eliminating connections that should be preserved. This excessive pruning is thought to contribute to the cognitive and social deficits in MHS — like a gardener who's lost their mind and hedges everything to the ground.