Fig. 7. Purinergic receptor antagonism of BDNF-dependent spiral ganglion neurite development. Cultures of P4 spiral ganglion explants were treated for three days with medium (control) or with addition of BDNF at 1 ng/ml or 10 ng/ml. The effect of P2X receptor activation on BDNF-dependent neurite development was assessed with ATPS (100 µM) and ,ßMeATP (100 µM). (A-F) Immunofluorescence images of spiral ganglion explants labeled for neurofilament. BDNF at 10 ng/ml. Scale bars: 500 µm. (G,H) Experiments comparing BDNF-induced neurite growth with and without ATPS (n=12-20 explants per group). (I,J) Experiments comparing BDNF-induced neurite growth with and without ,ßMeATP (n=12 explants per group). ^*P<0.05; ^**P<0.01.