Figure 2
The NMDA receptor mediates the influx of calcium into neurones in the presence of glutamate. tPA has been shown to cleave the NR1 subunit (triangle) of the receptor and, as a consequence, increases the concentration of intracellular calcium. By inhibiting tPA, neuroserpin is thought to protect neurons from the toxic consequences of excessive NMDA activity, termed ‘excitotoxicity’.