Brain Disorders
- Schizophrenia is characterized by psychotic episodes, hallucinations, delusions
- there may be multiple genes responsible for it
- treatment focuses on the use of dopamine
- amphetamine, which stimulates dopamine release
- drugs that alleviate symptoms of schizophrenia block dopamine receptors
- other neurotransmitters affected are serotonin and norepinephrine, and glutamate
- PCP blocks glutamate receptors and produces schizophrenia like symptoms
- Depressive illnesses are generally bipolar and major depression
- bipolar disorders involve mood swings from very high to very low
- in the manic phase, increased energy, risky behaviors, high self-esteem occur
- in the depressive phase, feelings of worthlessness, sleep disturbances, loss of interest, and risk of suicide occur
- those with major depression experience a low mood most of the time
- treatments include Prozac, electroconvulsive shock, lithium and talk therapy
- Alzheimer's disease
- is caused by mental deterioration which leads to dementia
- many symptoms occur, including confusion, memory loss, disorientation, and more
- diagnosis is usually made on autopsy, finding huge areas of the brain that have died or shrunk
- neurons have neurofibrillary tangles and senile plaques
- neurofibrillary tangles are bundles of degenerated neuron and glial processes
- senile plaques are clusters of beta-amyloid protein, cleaved from a normal protein found in healthy neurons
Figure 10. Normal Brain PET Scan. By US National Institute on Aging, Alzheimer's Disease Education and Referral Center
Figure 11. Alzheimer Brain PET Scan. Please compare the orange levels of activity seen in this brain and the normal brain in Figure 10. By US National Institute on Aging, Alzheimer's Disease Education and Referral Center
- Parkinson's disease
- characterized by difficulty in smooth movement, with muscle rigidity near death
- is caused by neuron death in the midbrain nucleus, called the substantia nigra, which release dopamine
- there is no known cause of the disease, probably is due to a combination of environmental and hereditary factors
- L-dopa has served as a treatment
- embryonic stem cell treatment may provide a cure in the future
