Atypical sphingoid bases generated in response to TNF exert direct cytotoxic effects on neurally differentiated MN9D dopaminergic (DA) cells. MN9D cells were plated in 96-well plates, and were neurally differentiated as described under Methods and exposed to treatement media alone (without BSA) or to various doses of 1-deoxysphinganine (1-deoxySa), 1-desoxymethylsphinganine (1-desoxyMeSa), or 1-desoxymethylsphingosine (1-desoxyMeSo) at the concentrations indicated in a complex with BSA (25 μM) for 48 hours. Cell viability was measured by the MTS assay described under Methods. All values represent group means +/− SEM, n = 3–4. One-way ANOVA with Tukey’s post-hoc, * denotes difference from treatment media alone (without BSA) at p < 0.05, *** denotes difference from media alone at p < 0.001.