Microglia-Mediated Synaptic Pruning Modulation to Optimize Functional Connectome Efficiency

This hypothesis proposes that targeted modulation of microglial synaptic pruning activity can restore optimal functional connectivity patterns in diseased neural networks. Microglia express complement receptor 3 (CR3) and fractalkine receptor (CX3CR1) which mediate activity-dependent synaptic elimination through complement tagging of synapses marked by C1q and C3. In pathological conditions, aberrant microglial activation leads to excessive or insufficient synaptic pruning, disrupting functional network topology and information processing efficiency. By pharmacologically or genetically modulating CX3CR1 signaling or complement cascade components, we can fine-tune microglial pruning behavior to selectively eliminate weak or maladaptive synapses while preserving functionally important connections. This approach targets the dynamic remodeling of synaptic connectivity rather than structural white matter integrity, focusing on optimizing signal transmission patterns and network efficiency metrics derived from functional neuroimaging. The intervention would involve CX3CR1 agonists or antagonists, complement inhibitors, or microglial phenotype modulators administered during critical periods of network reorganization. Success would be measured through functional connectivity analyses, graph theory metrics of network efficiency, and behavioral assessments of cognitive function, rather than diffusion tensor imaging of white matter tracts.