The effect of lentiviral expression of HINT1 on WIN55,212-2-mediated neuroprotection against NMDA insult. The cell cultures from WT and HINT1-/- mice were infected with 0.1 or 3 μL of lentiviral particles and exposed to NMDA for 24 h in the absence or presence of 100 nM of WIN55,212-2. Cell death was measured by LDH efflux into the medium. The data shown represent the mean ± S.E.M. from 20 wells per condition. * Significant difference compared to NMDA alone, p < 0.05. Bottom: Fluorescence photomicrographs of NMDA-treated HINT1-/- cortical cell cultures (A) uninfected or infected with HINT1 lentiviral particles either (B) without or (C) with WIN55,212-2. The cells were immunolabelled with an anti-MAP2 Ab (green). The nuclei were counterstained with 4,6-diamidino-2-phenylindole.