GABA is an inhibitory neurotransmitter in the central nervous system that was first isolated from mouse brain in the 1950s. It exists in two types of receptors - GABA A receptors which are ligand-gated ion channels and GABA B receptors which are G-protein coupled receptors. GABA is synthesized from glutamate by the enzyme GAD and acts to hyperpolarize neurons, reducing neuronal excitability. Drugs like barbiturates and benzodiazepines enhance the effects of GABA to produce sedative and anxiolytic effects. Deficiencies in GABA can lead to symptoms of anxiety, depression, and restlessness.

1. ID:141-29-669

2. Presentation topic:
GABA

3. Content:
• Introduction
• Discovery
• Synthesis of GABA
• Classification of GABA receptor
• Mechanism action of GABA
• Example of some drug that act on GABA
• Function of GABA.
• Deficiency of GABA.

4. Introduction:
• Gamma-Amino Butyric acid (GABA) is an amino acid which acts as a
neurotransmitter in the central nervous system.
• It inhibits nerve transmission in the brain, calming nervous activity.
• Chemical formula: 𝐶4 𝐻9 𝑁𝑂2
• GABA is a zwitter ion with deprotonated carboxyl group and protonated
amino group.

5. • In 19th century – was known as metabolite of plant and microorganisms.
• In 20th century – was isolated as amino acid in the brain of mouse through
paper chromatography.
• In 1950 Robert and Frankel discovered that GABA act as inhibitory
neurotransmitter in human brain.
Discovery:

6. Synthesis:
• Synthesized from amino acid L-glutamic acid in present of GAD.
• Glutamic acid decarboxylase (GAD) present in neurons, pancreatic cells
and in body fluid.
• GAD acts as a catalyst that removes carboxyl group from glutamate and
produce GABA.

7. Classes of GABA receptor:(2 types)
𝑮𝑨𝑩𝑨 𝑨 Receptor:
• It has pentameric structure.
• It has structural & functional similarity with
Ligand-gated ion.
• Each GABA-A receptor contain two alpha ,two
beta, and one gamma subunit.

8. 𝑮𝑨𝑩𝑨 𝑩 Receptor:
• They are hetro dimers.
• GABA-B has been cloned to b1 & b2 subunits.
• B1 subunit has GABA binding site while B2
subunit interact with G-protein.
• Two biological action:
-Decrease 𝐶𝑎2+ conductance
-Increase 𝐾+ conductance

9. How it works?
• Most of the sedative and hypnotic
drug(Barbiturate & Bzds) either binds
with α, β or γ subunits that activated
GABA receptor thus opening of
chloride channel that causes
hyperpolarization of cells and finally
depression of CNS.

10. Example of some drug that act on GABA
receptor:

11. Function of GABA :
• Relieving anxiety .
• Relieving pain.
• Regulating the release of sex hormones.
• Treating ADHD(Attention deficit hyperactivity disorder).
• Burning fat.
• Stabilizing blood pressure.
• Decrease blood sugar level in diabetics.

12. Top 3 GABA deficiency symptoms:
1. Anxiety &
depression.
2. General
uneasy
feeling.
3. Can’t sit for
long period of
time.