The target: a neurotransmitter called glutamate and its receptors, which malfunction in the forebrain of psychotic patients.

FORBES: Betting on the brain

These receptors interact with the neurotransmitter glutamate, the levels of which seem to be out of balance in depression.

WSJ: Drugs to Relieve Depression in Hours Not Weeks

And the peroxynitrite-mediated nitration of NMDA receptors leads to the release of glutamate and the influx of calcium which kills brain cells.

FORBES: The Lessons Of Failure: What We Can Learn From Bapineuzumab's Blowup

Guilford researchers hope to find a chemical that can block this enzyme, thereby stopping the toxic effects of glutamate without having to bludgeon brain-cell receptors with noxious chemicals.

FORBES: Repairing The Brain

They also block other dopamine receptors linked to different neurotransmitters such as those for serotonin and glutamate.

FORBES: Silencing the Voices