FIGURE 7.

Glutamate-induced OL death is ceramide-dependent. A, CerS5 and CerS6 protein expression was analyzed in OLs during cell differentiation in culture by Western blot. Proteolipid protein is a marker for OL differentiation, and β-actin was used for normalization purposes. B, quantification of the ceramide synthases expression in cultured OLs during differentiation. C, OLs were exposed to glutamate with/without 20 μm fumonisin B1 (FB1) or 1 μm myriocin (MR) or 200 μm cystine, glutamate antiporter inhibitor, and cell death was quantified 24 h later. Data are mean ± S.E., *, p < 0.05, n = 12. D, OLs were exposed to 6 mm glutamate (Glut) with/without 20 μm FB1 or 1 μm myriocin and ceramide content was analyzed 24 h later. Data are mean ± S.E., *, p < 0.05, n = 12.