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resposens can be mediated by either D1 and D2 receptors, whereas presynaptic receptors
appear to be exclusively the D2 subtype.
Mechanisms of action different DA- receptors see below.
Recent cloning experiments expanded the family of DA receptors subtypes - D3, D4, D5.. There are found primarily in limbic areas (D3), medulla and frontal cortex (D4) or hippocampus (D5).
All antipsychotics (exempt clozapine like) have potent D2 receptor blocking action; antipsychotic potency has shown good correlation with their capacity to bind to D2 receptor. Phenothiazines and thioxanthines also block D1, D3 and D4 receptors.
Blockade of DA-ergic projections to the mesolimbic system and mesocortical areas is probably responsible for the antipsychotic action (because DA overactivity in limbic area is responsible for exacerbate schizophrenia).