II. Physiology
- Gamma-Aminobutyric Acid (GABA)
- GABA is a key inhibitory Neurotransmitter of the Central Nervous System
- GABA is synthesized from the Amino AcidGlutamate, an important excitatory Neurotransmitter
- Facilitated by the enzyme Glutamic Acid Decarboxylase
- GABA Receptor
- GABA Agonists bind GABA Receptors, resulting in inhibition
- GABA Receptor binding triggers chloride channel opening, with secondary chloride influx into the Neuron
- Chloride influx hyperpolarizes the Neuron (inhibits new Action Potentials from forming)
- Decreases the Neurons responsiveness to excitatory Neurotransmitters
- GABA Receptors are down regulated in chronic Alcohol Abuse
- GABA A Receptors
- Ligand gated ion channels (ionotropic receptors) are fast responding receptors
- Agonists: Benzodiazepines, Barbiturates, Propofol, Etomidate, Topiramate, Carbamates
- Antagonists: Flumazenil
- GABA B Receptors
- G-Protein coupled receptors (metabotropic receptors) are slow responding receptors
- Agonists: Baclofen, Gamma Hydroxybutyrate (GHB)
- GABA Agonists bind GABA Receptors, resulting in inhibition
III. Resources
- GABA Receptor (Wikipedia)