Figure 1.

Trypan-blue staining, a marker of neuronal injury, 24 h after a 30-min washout of synaptic blockers. (a) Approximately half of the neurons stained for trypan blue after a 30-min washout of synaptic blockers. (b) Few neurons were stained for trypan blue in cultures that remained in a synaptic blocker (5 mM kynurenate) or (c) that were treated with 40 μM PD098059 during the washout of blockers. Neurons were counterstained with basic fuchsin (pink).