GFAP and Stroke: Together, the comparable fractional anisotropy and peri-infarct Iba-1 immunoreactivity in PBS- and C3a-treated mice, and the reduced expression of GFAP and increased fiber tract density in C3a-treated mice, support the conclusion that intranasal treatment with C3a in the postacute phase after stroke promotes functional recovery at least in part by modulating neuronal connectivity and astrocyte reactivity.