There is a variety of neurotransmitters present in the body which also has a number of different functions. One such neurotransmitter is acetylcholine which in itself has an assortment of necessary occupations. In order to appreciate the complexity of this neurotransmitter, it's primary location in the neuro-muscular system and it's release mechanism needs to be addressed. Through this, the ACH's function and it's eventual fate can also be examined.
The neuromuscular junction is one of the major locations of acetylcholine. This neurotransmitter can be found in a specific quanta inside of synaptic vesicles. These vesicles are then induced to move through the movement of ions inside and outside of the cell membrane. After the flux of ions (sodium, potassium and calcium)is induced, the synaptic vesicles move towards the edge of the pre-synaptic membrane which is also called the active zone. This zone is where the neurotransmitter (ACH) is eventually released.
The release of acetylcholine after the ion induced movement of the synaptic vesicle is done through a handful of proteins. The first protein which initiates the release of ACH is the protein called cam kinase II. This protein is induced upon the influx of calcium which is then activated to release the synaptic vesicle attached to micro filaments called synapsin. After this, another protein called RAB attaches to the freed synaptic vesicle. This protein functions as a guide for the vesicle to reach the active zone of the pre-synaptic membrane. Upon reaching the active zone, the RAB detaches and the docking of the synaptic vesicle begins. Docking of the synaptic vesicle involves three different proteins which come together to form the core complex. These proteins (synaptobrevin, synapsin and SNAP 25), with the aid of two other proteins (synaptophysin and MUNC 18) fuse together forming the core complex which becomes some sort of a transport tube for the acetylcholine. After the fusion occurs,the ACH neurotransmitter is finally released.
The release of acetylcholine results in the binding of the neurotransmitter into a specific type of ion gate called nicotinic acetylcholine receptor. Upon the binding of ACH, the receptor/channel is gated in order flux ions needed to fire an action potential. Through this action potential, information is transferred down axons and networks of cells spanning the body. After the function of the released acetylcholine is completed, it is quickly hydrolyzed by free floating enzymes called acetylcholinesterase which diffuses the ACH into choline and acetate.
The diffused acetate and choline eventually become re-assembled to once again be the neurotransmitter acetylcholine. This is done under the influence of the enzyme called choline-O-acetyl transferase. This synthesizes the liberated acetate and choline into once again becoming acetylcholine.
In conclusion, the neuromuscular junction is the primary location of the neurotransmitter called acetylcholine. It is found inside synaptic vesicles which are induced to release ACH by a handful of proteins. This then results into the binding of the ACH into a specific transmitter gated ion channel which thus induces action potentials. Through this, information is transported throughout the nerve nets in the body.
Thus upon reviewing the different states and functional steps of the neurotransmitter called acetylcholine, it is much easier to understand the basic processes it performs and its importance in the various systems in the body.
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