Question

What is the most common neurotransmitter?

Answer 1

Neurotransmitters carry messages between neurons. They have no effect on the membrane voltage of neurons. They communicate by sending messages in the opposite direction.

Complete answer:
A neurotransmitter is a chemical messenger which facilitates the transmission of neural signals from a neuron to the target cell. They are manufactured by the neurons for the purpose of signal transfer. They are released into the synaptic cleft by synaptic vesicles present in the synapses. There are more than 500 identified neurotransmitters.
Neurotransmitters diffuse across the synaptic cleft upon release. They bind to their specific receptors on the postsynaptic neuron membrane. Neurotransmitter binding influences the repolarization or depolarization of the postsynaptic neuron. The exposure of a neurotransmitter to its receptor is generally short term.
The most common neurotransmitter is acetylcholine. Acetylcholine is an ester of acetic acid and choline, as its name suggests. Motor neurons release acetylcholine for the activation of muscles. It is a neurotransmitter used at the neuro-muscular junction. Acetylcholine functions as a neuromodulator in the brain along with its neurotransmitter functions. It functions both in the Central Nervous System (CNS) and Peripheral Nervous System (PNS).
Acetylcholine supports the cognitive functions of target areas in the central nervous system. Acetylcholine activates muscle proliferation in the peripheral nervous system.

Note:
Acetylcholine has been traced in some cells that do not have any neural origin.
Myasthenia gravis occurs due to inappropriate production of antibodies by the body against acetylcholine receptors which inhibits the transmission of acetylcholine signals. Drugs that inhibit acetylcholinesterase help treat myasthenia gravis.