Phosphorylation of S6 ribosomal protein is reduced with chronic rapamycin or LY 294002 treatment. A, Changes in S6 phosphorylation with time in vitro. Top: Representative Western blots of phospho-S6 (Ser 235/236) and total S6, from 0 to 7 DIV, and from 7 to 27 DIV. Bottom, Ratios of phospho-S6 (Ser 235/236) to total S6 are plotted (n = 4, average +/− STD, *p < 0.05, **p < 0.01). B, Immunohistochemistry micrographs of cultures with different treatments, Nissl stain is shown in red and phosphor-S6 is in green. C, Representative Western blot of pS6 (Ser235/236) and total S6 and comparison of pS6 (Ser 235/236)/S6 ratio in cultures treated with vehicle, rapamycin, or LY 293002. D, Representative Western blot of pS6 (Ser 240/244) and total S6, and comparison of pS6 (Ser 240/244)/S6 ratio in cultures treated with vehicle, rapamycin, or LY 294002 (***p < 0.001).