Question

what is the pathophysiology for schizophrenics ?

Answer 1

Dopamine pathway: dopamine is released in different level in each pathway.

1.Mesolimbic system is extended from ventral tegmental area to nucleus accumbens in the limbic system and it is site of pleasure and reward. Dopamine maintains the both function. When the dopamine level is altered produces some positive symptoms.

2. Mesocortical pathway: where it projects from ventral tegmental area to prefrontal cortex. It controls and regulates emotions and affect by the dopamine. If the dopamine is altered it causes negative effect, mainly neagative symptoms.

3. Nigrostriatal pathway: it is extends from the substantia nigra to basal ganglia where the dopamine level is unaltered. It controls motor movements. Chorea, tics are results from excess level of dopamine. Parkinsonism symptoms, dystonia symptoms are results from the decreased level of dopamine.

4. Tuberoinfundibulor pathway: it is extends from hypothalamus to the pituitary where the dopamine level is unaltered. It is pathway which controls prolactin release

Both the mesolimbic and mesocortical involved in the Pathophysiology of schizophrenia. But due to effect of antipsychotic at mesocortical, nigostraital pathway, tuberoinfundibulor pathway, may prone to catatonic schizophrenia and hyperprolcatinemia.

Mechanisms of schizophrenia: there are many mechanism involved in causing schizophrenia. They are

1. Dopamine level:   hyperactivity of dopamine in mesolimbic system and hypoactivity of dopamine in the mesocortical system causes positive and negative symptoms respectively

2. Reduction of glumatergic -N-Methyl –D- -Aspartate causes schizophrenia symptoms

3. Reduced function of interneuron and irregular function of myelination causes schizophrenia symptoms

4. Reduction of oligodentrocytes causes the schizophrenia

5. High level of immunomarkers in the case of inflammation and infection causes schizophrenia

6. Oxidative stress causes reduction and growth of oligodentrocytes

   

Due to etiological factors such as genetic factors, low socioeconomic factor, psychosocial factors

    Causes increased level of dopamine in the mesolimbic system and decreased   level of dopamine in the mesocortical system and reduced action of glutamate receptor and reduced function of interneuron and irregular function of myelienation and reduction of oligodentrocytes and high level of immune markers and oxidative stress affect growth of oligodentrities and high levels of serotonin

Due to factors    Increased the positive symptoms of schizophrenia by increased level of dopamine in the mesolimbic system and increased negative symptoms of schizophrenia by decreasing level of dopamine in the mesocortical system and in another mechanism of reduction of glutamatergic N- Methyl –D –Aspartate   receptor in the brain causes symptoms and some medication like ketamine causes negative and positive symptoms of schizophrenia

              Due to above reasons    Positive symptoms such as hallucinations delusions and negative symptoms of schizophrenia such as reduced speech, laziness, loss of interest and motivation