Dual role of inflammation in CNS disease.

Inflammatory responses in the CNS have usually been perceived to cause or contribute to neuron injury. However, emerging evidence suggests that inflammatory reactions can also be neuroprotective. The nervous and immune systems employ overlapping mechanisms and shared mediators that promote cross-talk between the two systems. Immune cells, for example, produce not only neurodestructive molecules but also factors that can support neuroaxonal growth, survival, and plasticity. This might explain why inflammatory reactions may contribute to both injury and protection of neurons. The dual role of CNS inflammation also has important therapeutic implications that are only beginning to be explored.