(OT) Info on Benzodiazepines - and videos

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HOW DO BENZODIAZEPINES AFFECT YOUR BODY?

Benzodiazepines are general central nervous system (CNS) depressants.

They are all very similar chemically. All benzodiazepines act by

enhancing the actions of a natural brain chemical, GABA

(gamma-aminobutyric acid). GABA is a neurotransmitter, an agent which

transmits messages from one brain cell (neuron) to another. The

message that GABA transmits is an inhibitory one: it tells the neurons

that it contacts to slow down or stop firing. Since about 40% of the

millions of neurons all over the brain respond to GABA, this means

that GABA has a general quietening influence on the brain: it is in

some ways the body's natural hypnotic and tranquillizer. This natural

action of GABA is augmented by benzodiazepines which thus exert an

extra (often excessive) inhibitory influence on neurons.

The way in which GABA sends its inhibitory message is by a clever

electronic device. Its reaction with special sites (GABA-receptors) on

the outside of the receiving neuron opens a channel, allowing

negatively charged particles (chloride ions) to pass to the inside of

the neuron. These negative ions " supercharge " the neuron making it

less responsive to other neurotransmitters which would normally excite

it. Benzodiazepines also react at their own special sites

(benzodiazepine receptors), situated actually on the GABA-receptor.

Combination of a benzodiazepine at this site acts as a booster to the

actions of GABA, allowing more chloride ions to enter the neuron,

making it even more resistant to excitation. Various subtypes of

benzodiazepine receptors have slightly different actions. One subtype

(alpha 1) is responsible for sedative effects, another (alpha 2) for

anti-anxiety effects, and both alpha 1 and alpha 2, as well as alpha

5, for anticonvulsant effects. All benzodiazepines combine, to a

greater or lesser extent, with all these subtypes and all enhance GABA

activity in the brain.

As a consequence of the enhancement of GABA's inhibitory activity

caused by benzodiazepines, the brain's output of excitatory

neurotransmitters, including norepinephrine (noradrenaline),

serotonin, acetyl choline and dopamine, is reduced. Such excitatory

neurotransmitters are necessary for normal alertness, memory, muscle

tone and co-ordination, emotional responses, *endocrine gland

secretions*, heart rate and blood pressure control and a host of other

functions, all of which may be impaired by benzodiazepines. Other

benzodiazepine receptors, not linked to GABA, are present in the

kidney, colon, blood cells and adrenal cortex and these may also be

affected by some benzodiazepines. These direct and indirect actions

are responsible for the well-known adverse effects of dosage with

benzodiazepines.

Contrary to a popular misconception, benzodiazepines do not actually

increase the organic synthesis of GABA. As stated, they enhance the

action of existing GABA. Actually, benzodiazepines can, over time,

decrease the synthesis of GABA in certain areas of the brain. This is

one of numerous theories attempting to explain the occurrence of

" paradoxical " symptoms .

http://youtube.com/watch?v=FEIg1as2ppc

sherie