CGRP induces a prolonged increase in expression of GFAP in astrocytes. Spinal cord sections were obtained from control animals (CON), animals 2 hours post CGRP injections, or animals 24 hours post CGRP injection. (A) Images of spinal cord tissues stained for GFAP are shown in the top panels. Magnification bar = 50 μm. The same sections costained for GFAP and DAPI are displayed in the bottom panels. (B) The average fold change ± SEM of GFAP staining intensity from control values is reported (n = 3). # P < 0.01 when compared to control values.