Dopamine receptors levels (especially in the prefrontal cortex) are lower than patients without schizophrenia. However, these D1 receptors are increased in the parieto-temporal cortex in patients with schizophrenia. D2 mRNA levels are also increased in the frontal cortex. Antipsychotic medications used to improve schizophrenia symptoms in patients have shown that the most effective results involve dopamine and its interaction with neurochemical pathways (GABA, serotonin, etc).