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The Nervous System

Wernicke's area is part of the auditory and visual associations cortex. This region is responsible for
the analysis and formation of language content. For example, patients with lesions in this area:

1. Are unable to name objects
2. Are unable to understand the meaning of words
3. Articulate speech readily but usually nonsensically

Diseases of the Limbic System

There are several well known diseases that are disorders of the limbic system. A few are:

1. Psychosis
2. Schizophrenia
3. Depression

An increased DA response in the limbic system results in schizophrenia. DA may be synthesized
or secreted in excess, DA receptors may be supersensitive, and DA regulatory mechanism may be
defective. Symptoms are decreased by drugs which block DA receptors. Symptoms of schizophrenia
are:

1. Loss of touch with reality
2. Decreased ability to think and reason
3. Decreased ability to concentrate
4. Decreased memory
5. Regress in child-like behavior
6. Altered mood and impulsive behavior
7. Auditory hallucinations

Symptoms may be so severe that the individual cannot function.

Depression is caused by decreased levels of NE and/or serotonin in the limbic system. Drugs
which increase NE and/or serotonin decrease the symptoms of depression. Depression is the most
common major mental illness and is characterized by both emotional and physical symptoms.
Symptoms of depression are:

1. Intense sadness and despair
2. Anxiety
3. Loss of ability to concentrate
4. Pessimism
5. Feelings of low self esteem
6. Insomnia or hypersomnia
7. Increased or decreased appetite
8. Changes in body temperature and endocrine gland function

10 to 15% of depressed individuals display suicidal behavior during their lifetime.

Another common form of depression is manic depression. Manic is an acute state characterized by:

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