One of the catecholamine NTM based on amines.One amine produce both excitatory and inhibitory.Post synaptic potentials depending on post-synaptic receptors.It is involved in movement, attention, learning and reinforcing effects of drugs that people tends to abuse.
Bio Synthesis
- It is synthesized by an essential amino acid tyrosine.
- An enzyme converts tyrosine into L-Dopa.
- Another enzyme converts L-Dopa into Dopamine.
In liver
Tyrosine____ L-Dopa____ Dopamine____ No-epinephrine
L-Dopa
It is a biological active form of dopamine the precursor of catecholamine often used to treat for Parkinson because of its effect a dopamine agonist.
Controlling Drugs of Dopamine
1. Agonist
A drug which facilitate the effects of a particular neurotransmitter on the post-synaptic cell.
2. Antagonist
A drug that oppose or inhibit the effects of a particular NTM on the post-synaptic cell.
Systems of Dopaminergic Neuron
The brain contains three important systems of dopaminergic neuron.Three systems are found in dopamine system in blood is called dopaminergic neuron system.
1. Nigrostriatal System
It means the system of neuron which originate in the substatia nigra and project their axons to neostriatum which is important part of basal ganglia involved in the control of movement.
2. Mesolimbic System
A system of dopaminergic neuron originate in the ventral tegmental area and terminating their axons in the frontal cortex, amygadala and hypo-campus.
3. Mesocortical System
The system of dopaminergic neuron originating in the ventral tegmental area and terminating in the pre-frontal cortex located in the ventral tegmention area.These neuron effect such function as formation of short-term memory, planing preparation and problem solving.
Receptors of Dopamine
At least five types of dopamine receptors.
D1, D2, D3, D4, D5
D1 or D2 are more common receptors.
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