<prompt> Major mechanism of action of typical anti-psychotic drugs is:-Dopamine D1 receptor blockadeDopamine D2 receptor blockadeDopamine D3 receptor blockadeDopamine D4 receptor blockade  <response>: Antipsychotic drugs are divided into typical and atypical. Typical antipsychotic drugs mainly act by blocking D2 receptors of dopamine. Atypical drugs mainly act by blocking 5HT2 receptors of serotonin. 