GABA is an amino acid (protein building block) that acts as a
neurotransmitter. Its function is to inhibit nerve cells from
over-firing, lowering excitability. Working together with some of the
B-complex, it lowers anxiety and prevents stress chemistry from reaching
certain parts of the brain. It acts as a natural tranquilizer, or a
"braking" mechanism.

With chronic use, alcohol changes the protein areas of GABA receptors,
and this alteration is responsible for the effect of alcohol withdrawal.
Alcohol also depletes zinc and the B-complex, both needed by GABA in
order to function properly.

GABA receptors are in many parts of the brain, and alcohol's sedating
effect on GABA, affects many functions, including judgment.

Chronic alcohol use and its alteration of GABA, causes the brain to
adapt and depend on alcohol's depressant effect to function. When
alcohol is withdrawn, an alcohol dependant person experiences anxiety,
emotional pain, trembling, muscle tension, and depending on the severity
of alcohol dependence, convulsions or even death. This GABA alteration,
cripples the ability to deal with stressors and causes the dependant
person to crave alcohol to relieve the anxiety.


Excerpt:

"GABA is found throughout the central nervous system (CNS), assuming an
ever-enlarging role as a significant influence for pain, stress,
anxiety, depression as well as stress induced illness.*

If* you examine in a step-by-step process of what happens in the brain
when you feel stress and anxiety, you could see how GABA works and slows
down messages.* Panic, anxiety or stress-related messages begin to
release numerous signals, and concurrently, a physiological response
begins to take place the fight or flight syndrome.

The unceasing alert signals from the limbic system eventually overwhelms
the cortex ( the decision making part of the brain), and the ability of
the rest of the stress network becomes exhausted.* The balance between
the limbic system, and in fact, the rest of the brain to communicate in
an orderly manner depends critically on inhibition.* GABA inhibits the
cells from firing, diminishing the anxiety-related messages from
reaching the cortex.


GABA fills certain receptor sites in the brain and the body.* This
slows down and blocks the excitatory levels of the brain cells that are
about to receive the anxiety-related, incoming message.* When the
message is received by the cortex, it does not overwhelm you with
anxiety, panic or pain.* You are able to maintain control and remain
calm.* But, if you are under prolonged stress or anxiety, your brain
exhausts all the available GABA and other inhibitory
neurotransmitters.* This allows anxiety, fear, panic and pain to hit
from every direction.*

Your ability to reason is diminished.* In a full blown anxiety or
panic attack physical symptoms include excessive sweating, trembling,
muscle tension, weakness, loss of control, disorientation, difficulty in
breathing, constant fear, headaches, diarrhoea, depression and unsteady
legs.

GABA can mimic the tranquillizing effects of Valium or Librium without
the possibility of addiction or fear of being sedated.* *

Human behavior involves the functioning of the whole nervous system, and
the nervous system needs amino acids.* GABA, glutamine and glycine are
vital for energy and the smooth running of the brain functions.* B6
(pyridoxine) is GABA's most important partner."

http://www.internalhealth.com/gaba.htm