Viabilities of single-sorted cells plated in separate wells. Cell viability in each of the twelve sub-fractions with (B) and without (A) NGF. Left, average for each subfraction; middle, average for SSn; right, average for FSn. Shading corresponds to that in Fig. 4C. Statistically significant at *P < 0.05; **P < 0.005. C: SER versus NGF for each subfraction. The slope of the line is 1.