What Are Neurotransmitter Substances?

Any substance, such as acetylcholine or dopamine, are responsible for transmitting nerve signals across a synapse between two neurons as well as relay, amplify and modulate signals between a neuron and another cell.

Of the neurotransmitters that are known I have compiled a brief list as well as function as follows:

-Acetylcholine activates muscle's

-Norepinephrine and dopamine play a role in attention and focus (dopamine plays a role in drug addiction) , serotonin and norepinephrine play roles in major depressive and other psychiatric disorders, melatonin (plays a role in the sleep pattern based on the exposure of the retina to light, the more light the less melatonin is produced the less light the more melatonin is produced), histamine (plays a role in allergies such as sinus infections)

-Glutamate (is involved in cognitive functions like learning and memory) , gamma aminobutyric acid (plays a role in the regulation of muscle tone and is used to treat DPN-diabetic peripheral neuropathy), aspartate (is not a critical neurotransmitter but plays a role in fatigue), glycine (possible use as an antipsychotic)

-adenosine (plays a role for sleep and sex drive), ATP (adenosine triphosphate is involved with cellular metabolism), GTP (Guanosine triphosphate is indicated in protein synthesis)