Yes. They can serve both as a neurotransmitter and as a hormone.
No, not usually however there may [easily] be an exception or two, considering the versatility of Atp.
Epinephrine
no
acetylcholine
neurotransmitter neurotransmitter neurotransmitter
GABA (Gamma-AminoButyric Acid) is the most common neurotransmitter producing inhibition in the brain.
The accepted terminology is either neurotransmitter or neuromodulator. The compounds are epinephrine, ACh, norepiniphrine, GABA, glycine, ATP , ADP, adenosine, glutamate, aspartate, substance P, Neuropeptide Y, LHRH and probably 2 dozen others. In addition NO (nitric oxide) acts as a neuronal released modulator (albeit not by synaptic release).
no
mitochondria provide adenosine triphosphate (ATP) which in turn supplies the energy for synthesizing new neurotransmitter or transmitter substance.
neurotransmitter
neurotransmitter are not a natural opite
Dopamine are the feel good neurotransmitter.
acetylcholine
neurotransmitter neurotransmitter neurotransmitter
GABA (Gamma-AminoButyric Acid) is the most common neurotransmitter producing inhibition in the brain.
GABA is a neurotransmitter, it is the primary inhibitory neurotransmitter of the nervous system
The substance that is released at an axonal ending to propagate the nerve impulse to the next nerve or muscle is called
Dopamine is a feel good neurotransmitter.
Histamine is a neurotransmitter produced by basophils (a type of white blood cell).