FIG. 6.
Dynorphins stimulate [3H]thymidine incorporation into 21-day fetal rat brain cell aggregates. Aggregates were prepared from embryonic day 15 fetal rat brain and grown as described in Materials and Methods. Medium was replenished by 50% on every third day of culture. Dynorphins (1 μM) were added after 19 days together with protease inhibitors, and [3H]thymidine was present for the last 24 h. Control values for thymidine incorporation were 16 fmol/dish. Data are the mean ± SEM values of three experiments. *Significantly different from controls and nor-BNI–treated aggregates, p < 0.05.