Puma is required for 6-OHDA-induced cell death. Dissociated dopaminergic cultures derived from individual animals from Puma +/- ×Puma +/- matings were treated with 20 μM 6-OHDA for 24 hours. A) Cells were fixed and stained for TH. B) TH-positive cells were counted by an unbiased stereological method and survival expressed as a percentage of untreated control. Data were analyzed by one-way ANOVA (***, p < 0.001) with Bonferroni post-tests to compare to wild-type (+/-: **, p < 0.01; -/-: ***, p < 0.001) C) Cultures co-stained for TH and NeuN were counted to assess the survival of non-DA neurons. Data were analyzed by Student's t-test (**, p < 0.01) D) TH-positive neurite length was estimated by an unbiased stereological method. Data were analyzed by Student's t-test (ns).