Serotonin receptors antipsychotic drug blockade

Although the traditional neuroleptics do not bind to serotonin (5-MT) receptors with significant affinity, all of the atypical antipsychotics do. This observation has led to the hypothesis that 5-HT receptor blockade is an essential feature of the atypical antipsychotic drugs... 

FIGURE 10—11. Several different causes of dopamine deficiency may result in negative and cognitive symptoms. In schizophrenia itself, there may be a primary dopamine (DA) deficiency or a DA deficiency secondary to blockade of postsynaptic D2 dopamine receptor by an antipsychotic drug. If serotonin is hyperactive, this may also cause a relative DA deficiency by inhibiting DA release. Either primary or secondary DA deficiency in this pathway may cause cognitive blunting, social isolation, indifference, apathy, and anhedonia. 

The ratio between the blockade of serotonin receptors and dopamine receptors differs for various classes of antipsychotic drugs. True or False. 

The antipsychotic actions of neuroleptic drugs reflect blockade at dopamine and/or serotonin receptors. However, many of these agents also block cholinergic, adrenergic, and histamine receptors, causing a variety of side effects (Figure 13.3). 

It is believed that although antipsychotic medications block norepinephrine, serotonin, and acetylcholine, their primary action is as central dopamine antagonists (Galenberg, 1991 Meyer Quenzer, 2005). That is, these drugs block central dopamine receptors, particularly the Dj subtype, and thus inhibit dopaminergic neurotransmission in the brain. The postsynaptic receptor blockade in the limbic system is thought to reduce the schizophrenic symptoms. 

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