Figure 3.

Dopamine-related proteins altered in schizophrenic prefrontal cortex. Activation of dopamine D₂ receptors inhibits protein kinase A (PKA), which phosphorylates DARPP-32 at threonine 34. DARPP-32, when on its phosphorylated state, modulates protein phosphatase 1 (PP1) and consequently transcriptional factors, ion channels and receptors. NCS-1 inhibits D₂ internalization increasing its activation by dopamine. NCS-1 is upregulated and DARPP-32 is reduced in the prefrontal cortex (PFC) of schizophrenics (SCZ). D₂ receptor is the main target of antipsychotics. We demonstrated that levels of both NCS-1 and DARPP-32 are not modulated by typical and atypical antipsychotics. Our results suggest that these alterations are involved in the psychopathology but not in the treatment.