# A glial perspective on the extracellular matrix and perineuronal net remodeling in the central nervous system

## TL;DR

This review explores how glial cells influence the structure and function of the extracellular matrix and perineuronal nets in the brain, impacting both healthy and diseased states.

## Contribution

The paper highlights the role of glial cells as key regulators in the remodeling of the extracellular matrix and perineuronal nets in the central nervous system.

## Key findings

- Glial cells are central to the remodeling of ECM and PNNs in the CNS.
- ECM and PNNs exhibit dynamic changes that affect brain development and function.
- ECM and PNNs are involved in diverse functions like synapse stabilization and neuromodulation.

## Abstract

A structural scaffold embedding brain cells and vasculature is known as extracellular matrix (ECM). The physical appearance of ECM in the central nervous system (CNS) ranges from a diffused, homogeneous, amorphous, and nearly omnipresent matrix to highly organized distinct morphologies such as basement membranes and perineuronal nets (PNNs). ECM changes its composition and organization during development, adulthood, aging, and in several CNS pathologies. This spatiotemporal dynamic nature of the ECM and PNNs brings a unique versatility to their functions spanning from neurogenesis, cell migration and differentiation, axonal growth, and pathfinding cues, etc., in the developing brain, to stabilizing synapses, neuromodulation, and being an active partner of tetrapartite synapses in the adult brain. The malleability of ECM and PNNs is governed by both intrinsic and extrinsic factors. Glial cells are among the major extrinsic factors that facilitate the remodeling of ECM and PNN, thereby acting as key regulators of diverse functions of ECM and PNN in health and diseases. In this review, we discuss recent advances in our understanding of PNNs and how glial cells are central to ECM and PNN remodeling in normal and pathological states of the CNS.