Classical Neurotransmitters and Neuropeptides Involved in Schizophrenia: How to Choose the Appropriate Antipsychotic Drug?

Felix-Martin      Werner; Rafael      Covenas

Abstract

We summarize the alterations of classical neurotransmitters and neuropeptides, including their specific subreceptors, involved in schizophrenia. The essential susceptibility genes in schizophrenia and their coherence to neurotransmitter alterations are highlighted. In this sense, dopamine and serotonin hyperactivity in the mesolimbic system and the hippocampus is due to a reduced presynaptic inhibition carried out by GABA and glutamate, which is due to the susceptibility genes. A neuronal network in the brain regions involved in schizophrenia is developed in order to derive novel therapeutic approaches. A survey of the mechanisms of action of conventional and newer antipsychotic drug is given. We suggest the appropriate antipsychotic drugs considering the symptoms of schizophrenic and their possible side effects. It is important to examine the susceptibility genes in a cohort of patients in order to find out which patients profit more from antipsychotic drugs: those that exert a stronger D₂ antagonistic effect or those that exert a stronger 5HT_2A antagonistic effect. One question to be answered is whether refractory symptoms such as persistent acoustic hallucinations could be improved with novel antipsychotic drugs.

Keywords: Acetylcholine, cholecystokinin, dopamine, GABA, glutamate, neuronal network, neurotensin, serotonin.