The Nervous System
Lesson 9, Page 9 of 19

The hormone that is secreted by the pineal gland to induce sleep is melatonin.


Nearly one out of every 100 people suffer from Schizophrenia, a very severe mental illness. The symptoms of schizophrenia include positive symptoms such as hallucinations and delusions, and negative symptoms such as withdrawal and apathy. There are many theories about the cause, but schizophrenia is still a poorly understood disease. Researchers have discovered that there is over-activity of nerve cells in certain regions of the brain that release the neurotransmitter dopamine. However, this does not completely explain the contrasting symptoms that schizophrenics experience.

The neuroleptic drugs that block dopamine are used to treat schizophrenia. These can help with some of the positive symptoms, the hallucinations and delusions, but not with the negative symptoms, withdrawal and apathy. Additionally, one of the side effects of blocking dopamine secretion is disruption of motor coordination, resulting in side effects similar to the symptoms of Parkinson's disease.

Recently researchers have discovered that schizophrenics make too much of an enzyme involved in the production of certain fats important for normal brain cell activity. Drug companies are attempting to develop new drugs that can effect this enzyme's activity, in order to treat the disease.

Alzheimer's Disease

Alzheimer's Disease was named after a German neurologist, Alois Alzheimer, who first described the disease in 1907. It is a form of dementia that occurs primarily in older people, although it can strike those in their forties and fifties as well. Approximately 4-5% of people over 65 have symptoms of Alzheimer's disease. This number is expected to double by the year 2021 as the average age of the population increases and as cholesterol drug use expands, a major cause of Alzheimer's and other dementias. On the average people die 8 years after being diagnosed with the disease, although this can vary from 2 to 12 years. This makes Alzheimer's Disease the fourth largest cause of death after heart disease, cancer and stroke.

Alzheimer's disease starts with an impairment of short term memory but worsens until the victim has difficulties recognizing people they know. It is a difficult disease to diagnose because similar symptoms can be caused by other problems such as depression, alcoholism, virus infections, and even side-effects from medications. A diagnosis can only be made after death by autopsy. The brains of Alzheimer's patients are distinguished by the loss of acetylcholine-containing neurons and the presence of structures in the brain called plaques and tangles, which consist mostly of clumps of dead neurons. Scientists do not know whether the plaques and tangles are the cause of the disease or a consequence of some other problem in the brain. Since there is a significant loss of acetylcholine, drug treatments, such as tacrine and donepezil, (which have been mostly disappointing), have attempted to enhance the action of the neurotransmitter acetylcholine.

A new dietary supplement called Huperzine A has shown promise for Alzheimer's disease. Huperzine is a naturally-occurring chemical found in a traditional Chinese herb, Chinese club moss (Huperzia serrata.) Huperzine acts as an acetylcholinesterase inhibitor (inhibits the enzyme that breaks down the neurotransmitter acetylcholine.) Current research shows that the effects of huperzine are similar to but potentially more potent than the drugs tacrine or donepezil. Huperzine is without the negative side-effects of these drugs and is therefore much safer. Evidence also indicates that huperzine has neuroprotective effects, which means that it may help prevent further nerve damage. (We will discuss Huperzine A further in the herbal section of this lesson.)

Another extremely promising supplement for Alzheimer's and other dementias is coconut oil. Watch the fascinating video interview below. You probably haven't heard of this treatment yet because the drug industry is busy trying to figure out how they can produce a patented concentrate from coconut oil, but you don't have to wait. Add coconut oil to your diet now!


The symptoms of Alzheimer's disease can be mimicked by ________.

virus infections
all of the above

(Select the best answer and click on the "Continue" button.)