Figure 5.

p35-deficient cortical neurons are not resistant to DNA damage. Cortical neurons were cultured from p35 null (–/–), heterozygous (+/–), or wild-type (+/+) littermates and treated with camptothecin for 12 h. Neurons from the indicated number of mice with each genotype were cultured and tested individually. Cell membranes were lysed, and intact healthy nuclei were counted according to the protocol outlined in Materials and Methods. Survival was expressed relative to untreated cells for each animal and then grouped according to genotype. Untreated neurons from p35 –/– embryos did not display any difference in survival compared with +/+ or +/– neurons. Each error bar represents the mean ± SEM.