Molecular signals for glial activation: Pro- and anti-inflammatory cytokines in the injured brain

Injury to the central nervous system leads to cellular changes not only in the affected neurons but also in adjacent glial cells. This neuroglial acti vation is a consistent feature in almost all forms of brain pathology and a ppears to reflect an evolutionarily-conserved program which plays an import ant role for the repair of the injured nervous system. Recent work in mice that are genetically-deficient for different cytokines (M-CSF, IL-6, TNF-al pha, TGF-beta 1) has begun to shed light on the molecular signals that regu late this cellular response. Here, the availability of cytokine-deficient a nimals with reduced or abolished neuroglial activation provides a direct ap proach to determine the function of the different components of the cellula r response leading to repair and regeneration following neural trauma.