A role for calpain in optic neuritis.

Optic neuritis (ON) is one of the most commonly presenting symptoms of multiple sclerosis (MS), which is a neurodegenerative disease of the central nervous system (CNS) thought to be caused by an attack on myelin by autoreactive T cells and other immune cells. Experimental autoimmune encephalomyelitis (EAE) is a widely used model for MS and ON, which are characterized by demyelination, axonal damage, and neuronal death. The mechanisms of neurodegeneration are unclear; however, the calcium (Ca2+)-dependent neutral protease calpain is thought to be involved. The focus of this article is to summarize the evidence suggesting that calpain plays a role in the development of EAE-ON in Lewis rats.