Perineuronal nets and glial scar extracellular matrix components (PNN/ECM)

Perineuronal nets (PNNs) and the glial scar represent specialized assemblies of the neural extracellular matrix (ECM) that play critical roles in central nervous system (CNS) stability and pathology. PNNs primarily surround inhibitory interneurons and serve to crystallize synaptic connections, effectively closing the critical period of development and protecting neurons from oxidative stress (Sorg et al., 2016, Chemical Reviews). Following CNS injury, reactive astrocytes contribute to the formation of a glial scar, which, while limiting the spread of inflammation, creates a dense physical and chemical barrier to axonal regeneration (Silver and Miller, 2004, Nature Reviews Neuroscience). Both structures are rich in chondroitin sulfate proteoglycans (CSPGs), which are the primary inhibitory molecules preventing neural repair and plasticity (Fawcett et al., 2019, Nature Reviews Neuroscience). Therapeutic strategies often focus on the enzymatic digestion of these CSPGs using Chondroitinase ABC or the use of peptides like NVG-291 to block the interaction between CSPGs and their neuronal receptors, such as PTPσ (Lang et al., 2015, Nature). Modulating these ECM components holds promise for treating spinal cord injury, stroke, and various neurodevelopmental or neurodegenerative disorders by restoring a permissive environment for plasticity and regrowth.

Other names

Neural extracellular matrixChondroitin sulfate proteoglycan-rich matrixPNNsGlial scar ECMBrain extracellular matrix

Enzymatic degradation of chondroitin sulfate side chains to remove inhibitory signals; modulation of CSPG synthesis; antagonism of receptors like PTPσ and LAR that mediate the inhibitory effects of the ECM.