glutamatergic glutamatergic glutamatergic means "related to glutamate". a glutamatergic agent (or drug) is a chemical that directly modulates the excitatory amino acid (glutamate/aspartate) system in the body or brain. examples include excitatory amino acid receptor agonists, excitatory amino acid receptor antagonists, and excitatory amino acid reuptake inhibitors. main article: glutamate