Figure 4.

HC stimulated maximal neurite outgrowth at 100 nM, and neurite outgrowth stimulated by HC was inhibited by the glucocorticoid receptor antagonist mifepristone. (A) A dose-response curve is shown for both the average number of neurites per explant (•) and average length of neurites, in μm (▪) at increasing concentrations of HC (±SEM). The peak number of neurites/explants occurred between 100 and 500 nM HC. Peak average neurite length occurred between 100 and 500 nM HC. *P < 0.02 (100 and 500 nM HC compared with 0 nM HC). (B) Histograph of the mean number of neurites per explant (▪) and the average length of neurites, in μm (▪), for each treatment group (complete 10% EN2, 10% EN2 without HC, complete 10% EN2 with 1000 nM mifepristone, complete 10% EN2 with 1000 nM spironolactone) are shown (±SEM). Explants incubated in the presence of 1000 nM mifepristone produced significantly fewer and shorter neurites compared with explants in uninhibited EN2. Explants incubated in 10% EN2 containing 1000 nM spironolactone exhibited no change in neurite numbers or length compared with those incubated in uninhibited EN2. *P < 0.02 (compared with uninhibited EN2), **P < 0.05 (compared with uninhibited EN2).