Figure 5. Absence of α6 integrin subunit impairs process outgrowth in Bergmann glial growth cones. (A and B) Primary cerebellar glial cells were plated onto LN/Poly-D-Lysine substrates and analyzed by immunostaining. (A) Detection of α6 integrin subunit (green) and the glial marker BLBP (red).The α6 integrin subunit was expressed throughout glial fibers and located at the tip of glial processes. Insets represent enlargements of the glial process (arrow). Scale bars, 20 μm, 2.4 μm. (B) Immunostaining of GFAP (red) and actin (visualized by staining with phalloidin) (green). Control cells showed actin accumulation at level of the membrane ruffles and the tips of growth cone. By contrast, in α6-deficient glial cells the cell periphery and the leading edge of glial growth cone contained reduced actin amounts. The arrows indicate sites of actin accumulation in the glial cells. Scale bar, 20 μm. (C) Quantification of growth cone area measurements in control and α6fl/fl;nestin-Cre glial cells (n = 10, Student t test ***P < 0.001).