Glutamate and GABA neurotransmitter systems (Glu/GABA systems)

The glutamate and GABA systems represent the primary excitatory and inhibitory neurotransmitter frameworks in the mammalian central nervous system, respectively. Glutamate acts via ionotropic receptors like NMDA, AMPA, and kainate, as well as metabotropic receptors (mGluRs), to facilitate fast synaptic transmission and long-term potentiation (Purves et al., 2018). Conversely, gamma-aminobutyric acid (GABA) acts through GABA-A and GABA-B receptors to dampen neuronal excitability and maintain physiological stability (Petroff, 2002). The delicate equilibrium between these two systems, often termed the excitation-inhibition (E/I) balance, is essential for nearly all brain functions, including sensory processing, motor coordination, and higher-order cognition (Eichler & Meier, 2008). Dysregulation of this balance is a central feature of numerous neurological and psychiatric conditions, such as epilepsy, schizophrenia, and anxiety disorders (Treiman, 2001; Marin, 2012). Pharmacological interventions often target specific components of these systems, such as using NMDA antagonists for anesthesia or neuroprotection, and GABA-A modulators for sedation or anticonvulsant effects. However, because these systems are so ubiquitous, drugs affecting them often carry significant side effects like cognitive blunting, sedation, or potential for abuse (Braker et al., 2023). This entry is classified as incorrect because it describes a broad physiological system rather than a single, specific therapeutic target molecule.

Other names

Excitatory and inhibitory neurotransmitter systemsGlutamatergic and GABAergic systemsE/I balanceGlutamate-GABA axis

Drugs targeting these systems modulate neuronal excitability by acting as agonists, antagonists, or allosteric modulators of ionotropic and metabotropic receptors, or by inhibiting neurotransmitter reuptake and metabolic degradation to restore the homeostatic balance between excitatory and inhibitory signaling.