Neurotransmitters are the chemical messengers which are part of the nervous system.
They help the brain and spinal cord to control and regulate the whole body.
They are mostly formed in the nerves and released at the neuronal junctions.
There are many neurotransmitters in the body involved in different functions.
They can be classified based on their
- Physiological effects
- Functions in the body.
Types of Neurotransmitters
Based on chemistry there are four types:
Monoamines: These are also called biogenic amines. They form the largest set of neurotransmitters (NT’s) and control many key functions in the body.
Examples include; Dopamine, Norepinephrine, epinephrine, serotonin and histamine. Except serotonin and histamine, remaining others form a part of sympathetic system and also called as catecholamines. While histamine plays key role in wound healing and allergy. Whereas serotonin regulates stress and also emotions like anxiety, depression, memory etc.
Aminoacids: These are the ones which are basic aminoacids but have neurotranmitter function.
Ex:glutamine, glycine, GABA.
Glutamate is a exitatory type of transmitter in the brain. It is formed from the aminoacids glutamine. The glycine and GABA are inhibitory type of transmitters.
Peptides: These are large molecule NT’s in the body. Their chemical structure is a polymer of aminoacids. They are very large and limited and specific function in the body.
Examples include opiod peptides like endorphin, enkephalin, dynorphin, adrenorphin,aminorphin, leuomorphin etc.
They bind with opiod receptors and execute their function mostly in pain, emotion, food intake etc.
Choline based: These have a choline moeity in them bound to an organic acid.
These include Acetylcholine, butyrylcholine. Both of them are chemical transmitters in parasympathetic system. But acetyl choline forms a major portion of it. They execute their function through their action on the muscarnic and nicotinic receptors.