Fig. 7. Graded expression of BDNF may stimulate directed migration of granule cells. (A) Wild-type and Bdnf–/– cerebellar sections from P7 mice were immunostained with an antibody to BDNF. BDNF protein is present in a non-uniform distribution in the cerebellar cortex, with higher levels in the molecular layer and the IGL than in the EGL. (B) Purified wild-type granule cells were grown for 24 hours in Boyden chambers without BDNF (-), with 30 ng/ml BDNF added to both compartments (both) or with 30 ng/ml BDNF added only to the lower compartment (lower). As shown, a gradient of BDNF increased directed movement of wild-type granule cells through the porous membrane as compared to the movement with BDNF in both compartments, or to no BDNF. *P<0.05 (Student’s t-test) for control versus +BDNF, and for BDNF in both compartments versus BDNF in lower compartment only. Pooled results from three separate experiments are shown.
