FIGURE 1.

Chronic effects of various neurotrophic factors and cytokines on protein synthesis in cortical neurons. Neurons were treated without or with BDNF (50 ng/ml), NT-4 (50 ng/ml), NT-3 (50 ng/ml), insulin (10 μg/ml), nerve growth factor (NGF) (50 ng/ml), cilliary neurotrophic factor (CNTF) (10 ng/ml), glial cell line derived neurotrophic factor (GDNF) (10 ng/ml), human growth factor (HGF) (20 ng/ml), interleukin (IL)-1α (5 ng/ml), IL-1β (5 ng/ml), IL-2 (2.5 ng/ml), IL-6 (1 ng/ml), or interferon (IFN)-γ (5 × 10⁵ unit/ml) for 5 days. The incorporation of [³⁵S]methionine into newly synthesized proteins was analyzed. Bars represent the mean ± S.D. (n = 4). *, p < 0.05 (t test). Similar results were obtained in three or four independent experiments.