Fc-gamma Receptor Signaling

**What it means:** Fc-gamma receptors are "antenna" proteins on microglia that detect antibodies attached to targets (like synaptic connections). When an antibody flags a synapse, the Fc-gamma receptor tells the microglia: "Hey, prune this one!" It's the **"trim signal"** system for synaptic pruning. **Why it matters for MHS:** The multi-omics study found Fc-gamma receptor signaling strongly enriched among disrupted pathways in MEF2C-deficient microglia. This means the pruning antenna system itself may be malfunctioning — microglia can't tell which synapses to keep and which to prune, leading to chaotic over-pruning.