Question

How does schizophrenia affect the prefrontal cortex and the neuronal pathway? (can i please have a detailed explanation, as i'm very confused about the topic)

Answer 1

Schizophrenia it is a common type of long-term mental disorder because of large amount of distress and disability. Schizophrenia is a type of psychotic disorder. Psychosis is specific abnormalities of cognition and normal perception of reality. This may include hallucinations which are sensory perception without actual stimuli or delusions which are fixed false belief not explainable by a person with the idea of someone control the mind. Schizophrenia is often divided into three big categories.
1. Cognitive symptoms: abnormalities of attention Organization and planning abilities.
2. Negative symptoms: blunted emotions or loss of enjoy ability of activities.
3. Positive symptoms: typically the symptoms of psychosis

the abnormality is found in the brain of schizophrenia patients are

• fluid filled areas in the brain.Because of this there will be a reduction in the whole size of the brain tissue due to the filling of the cavity with fluid larger than normal.So the size of the cerebral cortex that covering the outer surface of the brain decreases.especially the some areas of the cerebral cortex covering the frontal and temporal lobe decreases. These areas have a lot functions to do with cognitive and perception functions. So these functions will be abnormal in schizophrenia.
• In some patients of schizophrenia the normal Organization of this cortical layer of the frontal and temporal lobe will be thinner with less tissue with disorganization and abnormal type of layering of the cells.in patients of schizophrenia something abnormal happens during the development of the brain. These portions of the brain do not develop normally and causes the disease.
• Some features of schizophrenia also appears to be as abnormalities in neuronal pathway with dopamine as the neurotransmitter that communicates between neurones and different parts of brain causing abnormal activities in certain parts of brain. For schizophrenia dopamine plays an important role in the activity of frontal and temporal lobe particularly the areas of cerebral cortex ,the major role in cognitive emotional and perceptional functions. The abnormalities of dopamine can also cause schizophrenia. A number of medications that affect the dopamine transmission of fund improve the symptoms of schizophrenia. There are collections of neurons in the brainstem which uses dopamine as the neurotransmitter. The aggregation of these cell bodies are called ventral tegmental area, VTA.The axons extend to different areas of the brain to release the dopamine to the other neurones. Some of such axons extend to the frontal cortex of the cerebrum. One of such pathway is meso cortico limbic pathway.Meso refers to the site where the neurons start which is midbrain. Cortico means the axons projecting into the the cortex of the cerebrum in the frontal lobe. 'Limbic' system is involved in in the emotions and perception activities of the brain. The symptoms is due to the abnormal activities of meso cortico limbic pathway which carry the dopamine from ventral terminal area to these areas of cerebral cortex. One way of thinking about schizophrenia which is surely incomplete at best, but that is a nice way to think about it is that abnormal activity in the meso cortico limbic pathway leads to dysfunction in parts of the frontal cortex that cause many, if not most of the cognitive symptoms of schizophrenia. Abnormal activity in parts of the limbic structures that cause many, if not most of the negative symptoms of schizophrenia and abnormal activity in parts of the temporal cortex that might cause many, if not most of the positive symptoms. In reality, however abnormalities that are involved appear to be far more complex than this simple idea and there is likely widespread dysfunction of many neuronal networks and multiple neurotransmitter systems throughout many different areas of the brain.

There are a number of clues that multiple kinds of things may be involved in causing the brain abnormalities responsible for schizophrenia.

• Genetic studies have suggested that the predisposition of schizophreniacan be inherited and there are several genes related to development of the brain or brain function that have been associated with the risk of the disease. It may be that genetic abnormalities increase the risk of the brain developing abnormally in certain situations. Hence genes may play major role in schizophrenia.
• some studies have suggested that certain types of physical stress on the mother during pregnancy such as infections during certain periods of the pregnancy periods that might be critical for the development of brain.this physical stress during the pregnancy may increase the risk of schizophrenia.
• And it does appear that psychosocial factors may play a role as well.Because some studies have suggested that a link to things such as negative interpersonal or family interaction styles during childhood because the neuronal network of the brain continue to develop after birth in response to life experiences. So it may be that negative life experiences only when the brain is still wiring itself may play some role in some cases of schizophrenia.