ABSTRACT
The central nervous system (CNS) is capable of dynamic immune and inŽammatory responses mediated by the activation of microglia, the brain resident macrophage population, and astrocyte reactivity. A growing body of evidence shows that the innate immune response exerts a dichotomous role in the brain. Under physiological conditions, microglia exhibit a resting phenotype that is associated with the production of anti-inŽammatory and neurotrophic factors. Microglia shift to an activated phenotype in response to a wide range of insults that activate speciŸc signaling pathways, thereby promoting an inŽammatory response necessary to further engage the immune system. The sustained inŽammation resulting in brain injury and pathology
11.1 Introduction .................................................................................................. 219 11.2 Connexin and Pannexin Expression in Microglia and Astrocytes ...............220
