Fig. 7.

Pharmacology of glutamatergic activation of SAPK/JNK and comparison of neuronal and glial cultures.A, Concentration–response curve for glutamatergic activation of SAPK/JNK in striatal cultures using immune-complex kinase assay. Striatal cultures were treated for 45 min at the concentrations indicated. B, Effects of glutamate agonists and antagonists on SAPK/JNK activity in striatal cultures. Immune-complex kinase assays were performed on cultures treated with glutamate (20 μm), NMDA (500 μm), kainate (50 μm), or tACPD (500 μm). The antagonists MK-801 (1 μm), APV (100 μm), and DNQX (100 μm) were added as indicated 10 min before the 45 min incubation with agonist. Data in A and Bwere typical of multiple experiments. NMDA,N-methyl-d-aspartate;tACPD,trans-(1S,3R)−1-aminocyclopentane-1.3-dicarboxylate;APV, 2-amino-5-phosphonovalerate; DNQX, 6,7-dinitroquinoxaline-2,3-dione. C, The effects of glutamate (100 μm) and mannitol (300 mm) for 45 min on SAPK/JNK activity measured by immune-complex kinase assay in standard (predominantly neuronal) striatal cultures (left) and glial striatal cultures (right). E18 striatal cell suspensions were seeded onto cell culture plates with or without a precoating of polyethylenimine for neuronal or glial cultures, respectively. Glial cells were cultured for 9 d in the presence of fetal calf serum until near confluent. Standard neuronal cultures (normally incubated in the presence of serum-containing medium for <1 d before it is replaced with defined medium) that were incubated instead in serum-containing medium still displayed a two- to threefold induction of SAPK/JNK activity with glutamate (data not shown).