The pathophysiology of schizophrenia is unknown. However, changes in dopamine regulation play a major role in both the symptoms and treatment of schizophrenia. In this graphic three of the different dopamine tracts are shown. In addition, the major effects of dopamine dysregulation in each tract is indicated.
It is important to notice that too much DA in the mesolimbic and too little in the mesocortical tracts leads to symptoms of schizophrenia. And any dysregulation of DA in the nigrostriatal will lead to side effects. However, since symptoms of psychosis are typically the most worrisome for patients, antipsychotic therapy is aimed at lowering DA levels in the brain.
Positive symptoms of schizophrenia such as hallucinations and delusions are the result of disregulation in which tract?
It is desirable to maintain low dopamine levels in all dopamine neuronal tracts.
Extra info: As can be seen in the nigrostriatal tract, low dopamine levels lead to symptoms of Parkinson's and low dopamine in the mesocortical tract contribute to the negative symptoms of depression.