Extracellular Matrix Modulation in Neural Plasticity

The neural extracellular matrix (ECM) comprises a dynamic network of proteins and polysaccharides that envelop neurons and glial cells, providing both structural support and biochemical signals that govern synaptic formation, stabilisation and remodelling. Key ECM constituents—glycosaminoglycans (GAGs) and their core proteoglycans—assemble into specialised lattices, notably perineuronal nets (PNNs), which emerge during late development to close critical periods of heightened plasticity. Modulation of ECM components, whether through enzymatic degradation, alteration of sulphation patterns or changes in biosynthetic enzyme activity, shifts the balance between synaptic stability and flexibility. This tuning of ECM architecture underlies learning and memory, recovery from injury and adaptation in neurodevelopmental and neurodegenerative disorders. Advances in understanding the molecular machinery that directs GAG chain initiation, elongation and modification are revealing precise levers for therapeutic intervention, from enhancing post-stroke rewiring to alleviating maladaptive fear retention. The interplay between neurons, astrocytes and microglia within the ECM milieu further refines plastic responses, indicating that targeting ECM modulation may unlock novel strategies for repair and rehabilitation across a spectrum of neurological conditions.

Research from Nature Portfolio

Recent studies have demonstrated that astrocytes and PNNs act in concert to preserve synaptic homeostasis in the adult cortex. Holes in the PNN lattice localise tripartite synapses—comprising pre- and post-synaptic terminals and astrocytic processes—that concentrate glutamate and GABA transporters, thereby restricting neurotransmitter spill-over and maintaining excitatory–inhibitory balance. Another investigation into glycosaminoglycan biosynthesis has elucidated how the enzyme EXTL3 selectively directs heparan sulfate assembly over chondroitin sulfate by recognising acidic motifs on core proteins, while default chondroitin initiation relies on CSGALNACT2. This molecular decision-making shapes ECM composition and influences synaptic plasticity. Foundational work has also revealed that PNNs decrease the specific membrane capacitance of fast-spiking interneurons, functioning as an electrostatic insulator that permits supra-physiological firing rates; degradation of these nets impairs rapid inhibition and may contribute to network hyperexcitability in pathological states.

Extracellular Matrix Modulation in Neural Plasticity publication trend

The graph below shows the total number of articles in extracellular matrix modulation in neural plasticity across all publications each year (not limited to Nature Index journals).

Technical terms

Extracellular matrix (ECM): A complex network of proteins and polysaccharides in the neural intercellular space that provides structural support and regulates cell signalling.

Perineuronal nets (PNNs): Specialised aggregations of ECM molecules, notably chondroitin sulfate proteoglycans, that enwrap certain neurons and stabilise synaptic contacts.

Glycosaminoglycans (GAGs): Long, unbranched polysaccharide chains within the ECM that bind proteins, modulate signalling and influence mechanical properties.

Proteoglycans: Core proteins covalently linked to one or more GAG chains, contributing to ECM architecture and interactive surfaces for growth factors and receptors.

Tripartite synapse: A functional unit in which two neuronal elements and an associated glial process interact to regulate neurotransmitter cycling and synaptic efficacy.

References

1. Astrocytes require perineuronal nets to maintain synaptic homeostasis in mice. Nature Neuroscience (2024).
2. Molecular mechanism of decision-making in glycosaminoglycan biosynthesis. Nature Communications (2023).
3. Casting a Wide Net: Role of Perineuronal Nets in Neural Plasticity. Journal of Neuroscience (2016).
4. Perineuronal Nets Enhance the Excitability of Fast-Spiking Neurons. eNeuro (2016).
5. Perineuronal nets decrease membrane capacitance of peritumoral fast spiking interneurons in a model of epilepsy. Nature Communications (2018).
6. Structural changes in perineuronal nets and their perforating GABAergic synapses precede motor coordination recovery post stroke. Journal of Biomedical Science (2023).
7. Glycosaminoglycans' for brain health: Harnessing glycosaminoglycan based biomaterials for treating central nervous system diseases and in-vitro modeling. Biomaterials (2024).
8. Acan downregulation in parvalbumin GABAergic cells reduces spontaneous recovery of fear memories. Molecular Psychiatry (2023).