Acetylcholine





Acetylcholine 3294
Photo by: RAJ CREATIONZS

Acetylcholine is the neurotransmitter produced by neurons referred to as cholinergic neurons. In the peripheral nervous system acetylcholine plays a role in skeletal muscle movement, as well as in the regulation of smooth muscle and cardiac muscle. In the central nervous system acetylcholine is believed to be involved in learning, memory, and mood.

Acetylcholine is synthesized from choline and acetyl coenzyme A through the action of the enzyme choline acetyltransferase and becomes packaged into membrane-bound vesicles . After the arrival of a nerve signal at the termination of an axon, the vesicles fuse with the cell membrane, causing the release of acetylcholine into the synaptic cleft . For the nerve signal to continue, acetylcholine must diffuse to another nearby neuron or muscle cell, where it will bind and activate a receptor protein.

There are two main types of cholinergic receptors, nicotinic and muscarinic. Nicotinic receptors are located at synapses between two neurons and at synapses between neurons and skeletal muscle cells. Upon activation a nicotinic receptor acts as a channel for the movement of ions into and out of the neuron, directly resulting in depolarization of the neuron. Muscarinic receptors, located at the synapses of nerves with smooth or cardiac muscle, trigger a chain of chemical events referred to as signal transduction.

Figure 1. The structure of acetylcholine.
Figure 1. The structure of acetylcholine.

For a cholinergic neuron to receive another impulse, acetylcholine must be released from the receptor to which it has bound. This will only happen if the concentration of acetylcholine in the synaptic cleft is very low. Low synaptic concentrations of acetylcholine can be maintained via a hydrolysis reaction catalyzed by the enzyme acetylcholinesterase. This enzyme hydrolyzes acetylcholine into acetic acid and choline. If acetylcholinesterase activity is inhibited, the synaptic concentration of acetylcholine will remain higher than normal. If this inhibition is irreversible, as in the case of exposure to many nerve gases and some pesticides, sweating, bronchial constriction, convulsions, paralysis, and possibly death can occur. Although irreversible inhibition is dangerous, beneficial effects may be derived from transient (reversible) inhibition. Drugs that inhibit acetylcholinesterase in a reversible manner have been shown to improve memory in some people with Alzheimer's disease.

SEE ALSO Neurotransmitters .

Jennifer L. Powers

Bibliography

Whittaker, V. (1990). "The Contribution of Drugs and Toxins to Understanding of Cholinergic Function." Trends in Physiological Sciences 11:8–13.

Internet Resources

Basic Neuropharmacology. "The Chemistry of the Nervous System." Available from http://www.ptd.neu.edu/neuroanatomy/cyberclass .

King, Michael W. "Biochemistry of Neurotransmitters." Available from http://web.indstate.edu/thcme/mwking .



Also read article about Acetylcholine from Wikipedia

User Contributions:

Pravin Chavda
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Mar 27, 2009 @ 4:04 am
its nice atttemp by auther to provide all the information regarding chemistry and electonocs.
shanda coleman
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Oct 13, 2009 @ 3:15 pm
I may be way off base, but have a question. I have had chest pain for quite some time now. I have been to doctor after doctor with no good results for the pain. I have been in the ER recently with chest pain. They told me my CPK enzymes were elevated. I saw a cardiologists and he did a few test...EKG, Echo, and one other to test for blocked arteries. They were all fine. He told me not to worry about the elevated CPK levels. I am still concerned as I am still having the chest pain everyday. I have read that it could be from muscle breakdown. Are the muscarinic receptors in this article connected to this in anyway? Thanks, Shanda
Paul Shelley
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Jan 18, 2010 @ 1:13 pm
I have been doing research into acetylcholine for the reason that I have been diagnosed with a tick disorder showing simple and complex ticks. finding that this neurotransmitter can cause ticks and adjusting the dopamine and serotonin levels has brought no progress I am interested to know what the symptoms would be if there was an imbalance of acetylcholine or acetylcholinesterase.
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Feb 6, 2010 @ 10:22 pm
My son has been having bad leg cramps when he plays a lot of basketball. We feel he is drinking plenty of electrolyte enhanced fluids and eating well (protein bars and drinks a banana, peanut butter and jelly on wheat bread, gels) and a vitamin as well. I read this on the internet. Is this true and will this help him?

Pickle juice As with mustard coaches have given pickle juice to their athletes with leg cramps. Cramps are sometimes caused by a deficiency in acetylcholine, the neurotransmitter that stimulates your muscles to work. Pickle juice has acetic acid, which helps the body make more acetylcholine. Take a few ounces of pickle juice.
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Oct 20, 2010 @ 2:14 pm
Hi
I would like to know that is the year of publication of this write, because I found it really interesting to mas thesis in neuropsichology, then to make a reference is need this.Then if you have something else to recommend me, i'm writing about acetilcholine and behavior.
Thanks you

Paola
Kacy Lange
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Oct 22, 2010 @ 11:11 am
I am interested in Acetylcholine and take Lecithin supplements to enhance my choline levels plus increase the dietary foods with this element. I have arthritis with pains across my chest that my arthritis specialist can not do anything about it. I have occasionally a "skin crawling" feeling that keeps me awake in pain. Since I've read a book about "introversion" I discovered that dopamine demotivates me where as acetylcholine levels work best for me. There is a blood test but my doctor doesn't see this test on the standard form for lab work. Does anyone know how the test can be done and how the results are measured?
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Nov 5, 2010 @ 1:01 am
IN WHAT PARTICULAR FOODS WILL FOUND THE ACETHYLCHOLINE
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Feb 2, 2011 @ 3:15 pm
I have been having different symptoms off and on for about five years now and the doctors first told me that I had early stage of CHF but two months after that I had a EKG done and everything was fine and know I am being tested for CIPD and MS. I am also having the Acetycholine test done my question is could all of my symptoms be connected to the Acetycholine exam.
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Mar 7, 2011 @ 8:08 am
I have been having different symptoms off and on for about five years now and the doctors first told me that I had early stage of CHF but two months after that I had a EKG done and everything was fine and know I am being tested for CIPD and MS. I am also having the Acetycholine test done my question is could all of my symptoms be connected to the Acetycholine exam.
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Apr 20, 2011 @ 2:02 am
i am currently doing acethycholine in memory. can acethycholine increase memory? if yes, what is the mechanism behind it?
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Oct 11, 2011 @ 10:10 am
what food and drink replenishes acetylcholine..i had a stroke and need it for muscle
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Nov 6, 2011 @ 1:01 am
I am final year student in engineering(biotechnology),My project is on the alzheimers disease.and i selected the acetylcholinesterase as a target .if i block the function of acetylcholinesterase .does it affect on other body parts or body mechanisms of metabolism? and f yes how? please tell me.
Giraud
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Dec 30, 2011 @ 11:23 pm
I have Multiple Sclerosis of the brain and currently take Aricept and Provigil to help brain function. What supplements and food can be taken to increase acetycholine?
How does one get tested for acetycholine levels.
Jackie
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Nov 22, 2012 @ 10:10 am
will acetylcholine help improve brain function in people with dementia?
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Nov 17, 2014 @ 9:09 am
Chemistry Explained has 18 letters. School has 6 letters. Chemistry explained is to help school. 18 divided by 6 equals 3. a triangle has 3 sides. Illuminati=Confirmed

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