FIGURE 4.

Neurite outgrowth in PC12 cells. PC12 cells grown in defined medium for 24 h received insect cell supernatant containing 0.7 nm purified mβNGF, rwtNGF, KKE, Δ9/13, KKE/Δ9/13, 7-45-103 (SS-2), KKE/7-45-103 (SS-4), 7-84-103 (SS-1), KKE/7-84-103 (SS-3), vector-treated controls (ctrl), or no treatment at all (cells). They were grown for an additional 48 h at 37 °C, 6.5% CO₂. Neurite outgrowth was assessed by comparing cells bearing processes >1.5 time their cell body in length to total cells counted. At least 200 cells were counted per well. Data are presented as mean ± S.D. with n = 3–4 independent expressions per data point. +, p < 0.01 significantly different from recombinant wild-type NGF.