Beyond NMDA and AMPA glutamate receptors: emerging mechanisms for ionic imbalance and cell death in stroke.

The glutamate receptor was one of the most intensely investigated targets for neuroprotection. However, numerous clinical trials of glutamate receptor antagonists for the treatment of stroke were unsuccessful. These failures have led to pessimism in the field. But recent advances could provide hope for the future. This minireview looks beyond the traditional mechanism of glutamate-receptor-driven excitotoxicity to identify other mechanisms of ionic imbalance. These advances include findings implicating sodium-calcium exchangers, hemichannels, volume-regulated anion channels, acid-sensing channels, transient receptor potential channels, nonselective cation channels and signaling cascades that mediate crosstalk between redundant pathways of cell death. Further in vivo validation of these pathways could ultimately lead us to new therapeutic targets for stroke, trauma and neurodegeneration.