Remodeling of extracellular matrix and epileptogenesis

Abstract

Extracellular matrix (ECM) in the brain is composed of molecules synthesized and secreted by neurons and glial cells, which form stable aggregates of diverse composition in the extracellular space. In the mature brain, ECM undergoes a slow turnover and restrains structural plasticity while supporting multiple physiologic processes, including perisomatic gamma-aminobutyric acid (GABA)ergic inhibition, synaptic plasticity, and homeostatic regulations. Seizures lead to striking remodeling of ECM, which may be essentially engaged in different aspects of epileptogenesis. This view is supported by human genetic studies linking ECM molecules and epilepsy, by data showing altered epileptogenesis in mice deficient in ECM molecules, and by evidence that ECM may shape seizure-induced sprouting of mossy fibers, granule cell dispersion, and astrogliosis. Therefore, restraining seizure-induced remodeling of ECM or suppressing the signaling triggered by the remodeled ECM might provide effective therapeutic strategies to antagonize the progression of epileptogenesis.