<prompt> Antipsychotic drugs act throughDopamine D1 receptor blockadeDopamine D2 receptor blockadeDopamine D3 receptor blockadeDopamine D4 receptor blockade  <response>: B Dopamine D2 receptor blockade Antipsychotics work by blocking a specific subtype of the dopamine receptor, referred to as the D2 receptor. Older antipsychotics, known as conventional antipsychotics, block the D2 receptor and improve positive symptoms. Second generation of antipsychotics or Atypical antipsychotics, block D2 receptors as well as a specific subtype of serotonin receptor, the 5HT2A receptor. It is believed that this combined action at D2 and 5HT2A receptors treats both the positive and the negative symptoms. Atypical antipsychotics include clozapine, risperidone, olanzapine, quetiapine, paliperidone and ziprasidone. 