GFAP expression is reduced in P2x7 brain. Serial sections were prepared from EAE immunized P2x7 null and WT mice at day 21 after immunization. At this time, the 3 WT mice all had clinical signs of 2.0; and the 3 P2x7 null mice had no clinical signs. Sections were stained with antibody to GFAP to detect activated astrocytes. Representative images show robust GFAP staining in WT frontal cortex (A) and thalamus (C), but not in corresponding areas of P2x7 null cortex (B) or thalamus (D). Significant staining for GFAP was found throughout the cerebellar grey and white matter in the WT mice (E) but was restricted to white matter (W) in P2x7 mice (F). S1HL, somatosensory hindlimb region; S1Trl, somatosensory trunk region; LV, lateral ventricle; HC, hippocampus; Th, laterodorsal thalamic nuclei; WM, white matter; ML, molecular layer; PL, Purkinje cell layer; GL, granule cell layer. Size bars are 200 μm.