Fig. 1.

TRPC5 knockout and calpain inhibition reduce sema3A-induced hippocampal growth cone collapse. (A) Untreated, cultured hippocampal neuronal growth cones from WT and TRPC5 null (Trpc5^−/−) mice, fixed and stained with the actin-binding peptide phalloidin conjugated to Alexa Fluor 568. (B) Growth cones from neurons treated for 5 min with 1 nM sema3A before fixation. (C) Growth cones from neurons preincubated with the calpain inhibitors calpain inhibitor III (5 μM) and calpeptin (10 μM) for 30 min and then treated with sema3A. (D) Growth cones from the indicated genotypes and treatments were counted and the collapsed fraction quantified (three coverslips from two separate experiments; n = 98–100 cones per condition). Ambiguous growth cones not closely resembling the examples presented were excluded from analysis. P values in text are calculated using Student t test.