Microglial Dynamics in Central Nervous System Health

Microglia are the resident immune cells of the central nervous system, originating from yolk-sac progenitors and attaining a highly ramified morphology in the mature brain. Beyond classical roles in defence and phagocytosis, these cells continually survey neuronal circuits, modulate synaptic connectivity and contribute to tissue homeostasis through the release of trophic factors and cytokines. Their dynamic processes extend and retract on the order of minutes, enabling rapid responses to alterations in local activity, metabolic state and injury. In development, microglia refine emerging networks by synaptic pruning and induction of spine formation, while in the adult they shape plasticity, influence sleep architecture and support metabolic demands. Dysregulation of microglial dynamics has been implicated in a spectrum of disorders—from neurodevelopmental and psychiatric conditions to neurodegeneration—highlighting their global significance. Current research emphasises the integration of signalling pathways, metabolic flexibility and receptor-mediated interactions as core mechanisms by which microglia maintain central nervous system health and limit pathological remodelling.

Research from Nature Portfolio

Recent studies have elucidated how microglial receptors and intracellular messengers orchestrate brain function. One investigation demonstrated that chemogenetic activation of Gi-coupled receptors in microglia elevates intracellular calcium, suppresses cortical norepinephrine transmission and promotes sleep, revealing a direct role for microglia in sleep–wake regulation. In parallel, metabolic profiling has shown that microglia import lactate via the monocarboxylate transporter MCT4 to drive lysosomal acidification. Loss of MCT4 impairs cargo degradation, disrupts synaptic pruning, enhances neuronal excitability and renders animals susceptible to seizures and anxiety-like behaviour. Together, these findings integrate receptor-mediated signalling with metabolic adaptability, underscoring multifaceted pathways through which microglia support neurophysiological homeostasis.

Microglial Dynamics in Central Nervous System Health publication trend

The graph below shows the total number of articles in microglial dynamics in central nervous system health across all publications each year (not limited to Nature Index journals).

Technical terms

Microglia: Resident CNS immune cells that survey and remodel neural circuits.

Synaptic pruning: The selective elimination of synaptic connections to refine neural networks.

Phagocytosis: Cellular process by which microglia engulf and degrade debris or synaptic elements.

Trogocytosis: ‘Nibbling’ of presynaptic structures by microglia without complete engulfment.

P2Y12 receptor: A purinergic receptor on microglia that mediates process motility and injury responses.

Monocarboxylate transporter MCT4: A membrane protein facilitating lactate uptake into microglia.

Gi-coupled GPCR: G protein-coupled receptor that inhibits adenylate cyclase and modulates intracellular signalling.

Calcium signalling: Intracellular Ca2+ transients that regulate diverse microglial functions, including motility and cytokine release.

References

1. Microglia regulate sleep through calcium-dependent modulation of norepinephrine transmission. Nature Neuroscience (2024).
2. Loss of microglial MCT4 leads to defective synaptic pruning and anxiety-like behavior in mice. Nature Communications (2023).
3. Microglial Interactions with Synapses Are Modulated by Visual Experience. PLOS Biology (2010).
4. Microglia remodel synapses by presynaptic trogocytosis and spine head filopodia induction. Nature Communications (2018).
5. Microglia contact induces synapse formation in developing somatosensory cortex. Nature Communications (2016).
6. The semantics of microglia activation: neuroinflammation, homeostasis, and stress. Journal of Neuroinflammation (2021).