Fig. 1.

Activation of CB1 receptors inhibits NMDA-induced cell death in DRG neurons and F-11 cells. Cells were exposed to NMDA (100 μM) for 24 h in the absence or presence of cannabinoid receptor agonist R-(+)-WIN 55,212-2 (500 nM). NMDA reduced the viability of cells by approximately 70% for DRG neurons and 80% for F-11 cells in the absence of WIN. The NMDA-induced cytotoxicity was reduced significantly in the presence of WIN. This WIN-mediated protective effect was blocked by the CB1 receptor antagonist SR141716A (500 nM), but not the CB2 receptor antagonist SR144528 (500 nM). Cell survival was not affected by either WIN, SR141716A, or SR144528 alone. Cell death was measured by the cytotoxicity index, as defined under Materials and Methods. Data shown are means ± S.E.M. for 20 wells per condition. *, p < 0.05 compared to treatment with NMDA alone, Scheffe's tests. †, p < 0.05 compared to NMDA + WIN condition.