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The Nervous System—Brain, Nerves and Mind

"If you gaze long into an abyss, the abyss will gaze back into you."
- Friedrich Nietzsche -

The close link between the mind and the brain took a long time for us humans to discover.  The ancient Chinese believed the heart was the true seat of the mind, while the brain was just excess bone marrow.  The Greeks thought the brain worked like a radiator, cooling the blood.  I remember talking to an old naturopath (Dr. Marsteller), who had participated in some early experiments in brain surgery at Hahnemann College in Philadelphia in the 1920's.  He told me they knew so little back then he thought the practice fell just short of legal murder.  Today, many of us think of the brain as a complex computer that processes information at lightning speed.  Others say the best analogy is that of a hologram, reflecting throughout our physical being any and all changes in nervous system energy or function.  But, whatever we think today, tomorrow it will be different.  Although they have progressed rapidly in the past decades, both neurobiology, the science of the brain and how it functions, and psychology are still in their infancy.  Nervous system diseases, including mental disorders and neurodegenerative conditions, remain among the most difficult to understand and to treat.  Nonetheless, I believe there are miracles awaiting us in the near future.  Herbal medicine will be part of this. As always, I like to look into the past, as well as the future.

The Ayurvedic Qualities of Mind

According to Ayurvedic medicine,  seen as a whole, the mind has three primary qualities.  The first is called suddha sattva, and it refers to a pure mind, with clarity of perception and filled with peace and love. Thesecond is called rajasa sattva, denoting an aggressive mind, filled with anger and desire. The third is called tamasa sattva, a mind filled with inertia and sloth.  The condition of pure mind promotes health, while the aggressive or slothful mind-sets promotes disease.
 
Functionally, there are three things I suggest you keep in mind if you want mental peace. First, your mental state largely depends on the usual suspects--lifestyle, sleep, good nutrition, exercise etc. Secondly, there is a well-developed system of traditional psychology which I judge to be of immense depth and benefit. See the offerings of the Institute for the Study of Human Knowledge mentioned in the resource guide.  Thirdly, practicing T'ai Qi, Yoga, deep relaxation, prayer or meditation enables us to reprogram and gain some voluntary control of our nervous system, so we can turn off stress and enter into a blissful mental state.

What it takes to Relax the Mind

If you think you understand this already, take note of this lecture given by marital arts Master Kuo Feng-chih to his students, described by Robert Smith in the book Pa-Kua. The last sentence gives one of the keys to health benefits. I will simplify for brevity:

Several months have passed since I began teaching you. Although we have practiced many hours, your progress is slow because you have failed to grasp the concept of the internal (nei chia). You must learn to quiet the mind and soften the muscles, an almost spiritual feat which depends upon the revolutionary idea that the mind can 'will' relaxation. You must practice this 'willing' of a tranquil flow from your eyebrows to the soles of your feet. You mind must travel this imagined route until all distracting thoughts are shut out, your nerve-ending sharpened, but your mind at ease, completely free of all impatience and anxiety. Your whole being must enter a state of bliss, and your mind  will thus become liberated. When this happens, your body and limbs will attain a happy unencumbered circulation of oxygen and blood. (rescended from Smith, 1983).

Ridiculously Simplified Nervous System Physiology

As we have discussed, the nervous system and its related systems are one of the three large primary systems controlling our bodies.  Nerve cells themselves are biological miracles.  The DNA in individual nerve cells is extraordinarily active, doing things scientists can only guess at.  Nerve cells process information in milliseconds with electrical and chemical pulses that travel along their length, feeding information into a geometrically expanding circuitous web.

The brain and spinal cord make up the central nervous system or CNS, while the peripheral nerves and ganglia comprise the peripheral nervous system or PNS.   The PNS is further divided into two subsystems, autonomic and somatic.  The autonomic division of the PNS controls involuntary bodily functions, including glands, smooth muscle, and the heart.  The somatic nervous system controls voluntary bodily functions.

The autonomic system is comprised of two subsystems, known as the sympathetic and parasympathetic systems.  The sympathetic nervous system is generally stimulatory in nature, and is known as the “fight-or-flight” system.  The parasympathetic nervous system is generally calming in nature.  Most organs in our bodies receive stimulation from both sympathetic and parasympathetic nerves, controlling the excitability or lack thereof of the organ in question.

Brain Chemistry Simplified

The body has many ways of signaling, necessary for coordination and control. For example, when the glands of the body release chemical messengers called hormones into the bloodstream, these act on receptor molecules anywhere in the body.  These “messages” can stimulate a cell to do many things, including manufacture chemicals like estrogen, or even cause changes in the operation of the genetic material—DNA (Ornstein, 1984).  The chemicals from a particular part of the body fit into locations on receptor molecules like a key fits into a lock.  Local messaging (paracrine signaling) works in a similar way, when neighboring cells communicate with chemical secretion "messages", as happens at sites of infection.

The nervous system has a special form of communicaton called neuronal signaling. It differs from hormonal signaling in that the "messages" travel over private lines, your nerve cells with their enlongated shape. The brain and nerves cells talk with each other via neurotransmitters, chemical messaging molecules that send information across the synapse (junction) connecting one nerve cell to another nerve cell or a muscle.  When an electrical impulse traveling along the nerve reaches the axon, this biochemical neurotransmitter is released and crosses the synapse to a synaptic receptor, where it stimulates or inhibits the receiving neuron.  There are more than 300 known neurotransmitters, including the endorphins and acetylcholine.  A class of neurotransmitters called neuropeptides can also deliver complex messages to other parts of the body, even to receptors on single immune system cells. 

We can also look at neurotransmitters as fingers on a hand, and the receptor sites as keys on a piano.  Each finger has its place on a particular key, and the resulting pressure produces an expected “note” or reaction.  Thus, the modern explanation of how the body accomplishes certain tasks is linked to its quite elaborate chemical messaging systems.

Signals received by cells have three basic actions (note: this understanding is constantly evolving):

1. If the cell receives adequate signal stimulation it survives.  Otherwise, it dies.
2. Additional signals beyond survival stimulate division (growth).
3. Other additional signals promote specialized changes known as cell differentiation (Alberts et. al, 1998).
Herbal medicines can act on the nervous or hormonal systems (or any cell) partly because they contain molecules with pieces that resemble the “keys” found in the chemical messaging systems.  These pieces fit into the receptor sites.  Phyto-estrogens, for example, are plant chemicals that gently mimic the action of the body’s natural estrogens, and can help alleviate the post-menopausal symptoms of estrogen deficiency women experience.  This is a case of an herb attaching to and stimulating a receptor site chemical reaction.  These herbs and other substances that stimulate receptor sites are called agonists.  Other herbs have the ability to attach to receptor sites and block the chemical reaction.  These agents are called antagonists.  Biochemists classify synapses into different groups according to the type of neurotransmitters they utilize.

A Few Good Brain Chemicals

Specific nutrients are required for your nervous system to function properly. For example, choline is a nutrient found within the B-complex that is essential for manufacturing the excitatory neurotransmitter acetylcholine.  Choline is found in grains, legumes and egg yolks and especially in lecithin.  A superior form of lecithin made with high levels of phosphatidylcholine is used in Germany for many liver disorders, including chronic hepatitis and cirrhosis (reported in Murray, 1996).
 
The brain uses acetylcholine for many processes.  This neurotransmitter is very important for memory (Canty and Zeisel, 1994), as well as movement, coordination and stamina via action on the skeletal muscles and the heart.  Cholinergic nerve synapses are those that release and respond to the acetylcholine.  Cholinergic chemicals are those that increase the production or release of acetylcholine, or prevent its degradation.  Because of this, researchers have been looking for ways to boost acetylcholine to improve memory in Alzheimer's patients and decrease the depression caused by bipolar disorder.  Theoretically, safe forms of plants or plant extracts might be beneficial to improve memory, strengthen muscles, promote peristaltic movement, and decrease eye pressure via this mechanism.  This is a fertile area for herbal research.

Ginseng root extracts (ginsenosides) have been shown in animal experiments to directly increase production of acetylcholine (Huang, 1999).

• Both shilajatu and ashwaghanda root are used as brain and memory tonics in Ayurvedic medicine.  In one rat study, Indian researchers found that several groups of extracts from these two herbs preferentially stimulated cholinergic cascades in the cortical and basal forebrain areas, increasing receptor capacity.  They concluded that this could help "explain the cognition-enhancing and memory-improving effects of extracts from ashwaghanda observed in animals and humans" (Schliebs, et. al, 1997).

• In one screening, the Chinese herb evodia fruit (Evodia rutaecarpa / wu zhu yu) strongly inhibited an acetylcholine-destroying enzyme.  In live animal studies it was shown to have strong anti-amnesia action, and a fraction was found to be more potent than Tacrine, the only drug for Alzheimer's disease approved by FDA (Park et al., 1996).  In TCM this strong-smelling herb is considered to be very hot and is used to warm the liver with signs of coldness, headache and stomach pain.  Therefore, I would only consider using it as part of a balanced formula in patients with both symptoms (amnesia and internal coldness).

Conversely, anticholinergic chemicals inhibit acetylcholine release and/or response.  Curare is a strong anticholinergic, which explains why it paralyzes muscles.

• The anticholinergic action of the herb Swertia japonica is effectively used in Japan to calm intestinal muscle spasms (Yamahara et. al., 1991).

• Ayurvedic doctors use suchi (Atropa acuminata), a relative of belladona, as a sedative, narcotic and antispasmodic.  Both belladonna and suchi contain the anticholinergic alkaloid atropine, long considered to be the "active ingredient." However, in an interesting demonstration of whole plant action, Italian researchers found in animal experiments they could produce "significant biological activity" using whole plant extracts which contained low levels of atropine (Mazzanti et al., 1988).

Adrenaline and Noradrenaline

Adrenaline and noradrenaline are neurotransmitters stored in the adrenal glands that control the adrenergic nerve synapses.  Adrenaline is released in emergency response to physical stress and tends to stimulate the heart and relax the muscles in the GI tract.  This helps explain the well-known “fight-or-flight” response, in which muscles must be stimulated to fight, while the bowels must be relaxed to remove waste quickly for rapid flight.  Oops.
Noradrenaline (also called norepinephrine) is similar in nature, but it does not relax the muscles of the lungs or increase heart output, but instead strongly constricts blood vessels to raise blood pressure. 

We have different types of adrenergic receptors that take up the adrenaline and noradrenaline released into our system.  The physical result of adrenaline or noradrenaline uptake depends on the type of receptor involved.  For example, beta-adrenergic receptors stimulate the heart, which is why “beta-blocker” chemicals are used to calm the heart and lower blood pressure.  The endorphins we produce in our bodies bind to opiate receptors and act as natural painkillers.

• Herbs such as opium poppy and corydalis rhizome (Corydalis yanhusuo) reduce pain by binding to opiate receptors (Stansbury, 1999).

• The alkaloid ephedrine, found in the TCM herb ephedra (ma huang), stimulates these receptors.  This explains why ephedra is known to relax and open the muscles surrounding the lungs in asthma, but too much will over-stimulate the heart and raise blood pressure.

•  Red pepper was examined in a controlled clinical study for its effects on dietary energy production.  Subjects received either 10 grams of red pepper or a placebo with their meals.  The herb recipients experienced increased energy (heat) production for 30 minutes and carbohydrate metabolism for a period of 150 minutes, after which metabolism returned to normal.  The effect was a result of a short-term beta-adrenergic stimulation (Yoshioka et. al., 1995).  This could prove useful for some patients who have difficult digesting carbohydrates.  It also means patients with hypertension taking beta-blockers might not want to eat large amounts of red peppers.  However, considering the short period of time and large amount of herb involved in the study, it is not cause for major concern. I wouldn't suggest eating ten grams (five teaspoons) of red pepper.  Traditional usage dictates mild dosage.

•  The powder of puskaramula root (Inula racemosa), traditionally used for asthma and allergies due to a potent bronchodilating effect (Pandey, 1996) was investigated in animal studies and found to have beta-adrenergic activity (Tripathi et. al., 1988).  TCM doctors use a related species inula flower (Inula chinesis / xuan fu hua) for wheezing excessive sputum, and to "direct the Qi downward," a very useful plant to stop vomiting and hiccups.  

Mood-Managing Neurochemicals

We achieve chemical management of mood through modern drug therapy by focusing on imbalances in a group of neurotransmitters called monoamines, which include serotonin, melatonin, dopamine, epinephrine and norepinephrine.  The body manufactures all of these neurotransmitters from dietary amino acids.  As with the other brain chemicals mentioned, mood-altering drugs either increase the production or inhibit the breakdown of these neurotransmitters, altering nerve cell stimulation.  Within the cerebral cortex, glutamate acts as the primary stimulatory neurotransmitter, and GABA (gamma amino butyric acid) acts as the primary inhibitory neurotransmitter.  Serotonin is also of particular importance, because it is a natural anti-depressant and tranquilizer (Murray, 1996).
 
It is important to maintain good levels of important brain chemicals.  However you must remember that mental and emotional symptoms are signs that something needs to be corrected.  Numerous foods and herbs act on the receptor sites that control mood, and your body can’t efficiently manufacture these neurochemicals without proper nutrition.  Taking a multi-vitamin and watching your diet is a good start, and should always be tried as a first step before using herbs. Ginseng root has been shown to raise brain levels of numerous monoamines (Wang et. al., 1995, Huang, 1999).

According to a report in the journal Lancet, melatonin is one of the natural ingredients of the commonly used anti-migraine herb feverfew (Murch et. al., 1997). I’m not sure what this might mean in a clinical application, but it is a surprising reminder that plants can contain very specific hormones that are known to influence human brain chemistry.  Melatonin, produced in the pineal gland, is related to circadian (day-night) cycles.  Feverfew is used to treat migraine headaches.  New Info - feverfew and cancer

People taking Monoamine oxidase inhibiting drugs (MAO inhibitor list) must avoid fermented cheeses, yeast-containing products, alcohol of any type, and pickled herring due to a chemical interaction with tyramine, an ephedra like chemical.  For the same reason, the herb ephedra should never be taken with these drugs.
Certain fractions of ginkgo leaf have shown strong MAO inhibiting action, which may partially account for its neuroprotective and neurorestorative effects (Wu et. al., 1999).  There is some theoretical concern that additive effects indicate it should not be taken with MAO inhibiting drugs (White et. al., 1996).  The same concerns have been raised for St. John’s wort, but so far there is no direct evidence of any problems in this regard.  Rather, it now seems that this herb exhibits broad-based neurotransmitter uptake inhibition of serotonin, dopamine, noradrenaline, GABA and L-Glutamate (Chatterjee et. al., 1998).  This action is strong, but because it is well distributed across many chemical pathways, strong interaction with other drugs in this class has not so far been problematic (Blad et al., 1994), although it does speed clearance of other drugs.  A similar argument can be made for kava root (Seitz  et al., 1997).

Nitric Oxide

The remarkable tiny gas molecule nitric oxide (NO) functions as a signaling molecule that works in response to nerve cell stimulation.  It penetrates directly into cells and sets off reactions.  It sends signals between nerve cells, and also to endothelial tissues (vessel linings), where it acts as a potent vasodilator. This unique vasodilating action is its most important action, and largely explains it importance in medicine.  When NO is released from nerves in the penis, it causes the blood vessel dilation required for erection, which is how the drug Viagra works (Alberts et. al., 1998).  NO also doubles as a destroyer molecule in activated immune cells (Anggard, 1994).  Numerous herbs have shown the ability to modulate nitric oxide activity in test tube and animal studies.  These studies have not reached the level of clinical significance yet, but they point to another area of research.

• Both ginkgo leaf and ginseng root extracts were able to induce cerebral blood vessel relaxation via NO pathways (Chen et. al., 1997).  This, of course, leads to increased blood and oxygen flow to brain tissues.

• Many plant flavonoids, including those found in green tea leaves, have shown anti-cancer effects in a variety of test tube and animal models.  One mechanism of action is through modulation of nitric oxide-related inflammation (Liang et. al., 1999).

Garlic bulb activates NO release, and in a controlled experiment, garlic-fed animals were able to neutralize a chemical that inhibited NO, preventing them from developing high blood pressure (Pedraza-Chaverri et al., 1998).

•  American ginseng root has shown the ability in animal studies to increase NO release in blood vessels, indicating a potential role in cardiovascular disease treatment (Yuan et. al., 1999).  Chinese ginseng root extracts have shown similar actions in heart tissue (Varga et. al., 1999).

• Other herbs that have shown effects on NO in test tube and animal studies include dandelion root (Kim et al., 1999), aged garlic (Ide and Lau, 1999), schisandra berries (Panossian et al., 1999), licorice root (Nose et al., 1998), and aloe vera leaf (Izzo et al., 1999).

Is That All There Is?

As I mentioned earlier, herbalists believe it is important to discuss not only the “hardware” of the brain and nervous system, but also its “software,” the mind and emotions.  All of these chemical reactions and responses are essential to our understanding of the nervous system, and focusing on hormones and neurotransmitters can certainly offer us insight into mental processes.  But we all know that they are only part of the answer.  Psychological factors obviously are involved in nervous system health.  I don’t believe we can improve our lives by simply taking “happy pills,” whether pharmaceutical or herbal.

One of the greatest difficulties the healer faces is a decision between the two basic thought trends that color most of what we do in this field.  The causal-mechanistic mode, which focuses on physical aspects of health, is common among scientists but also appeals to many practitioners of natural medicine.  I certainly do this myself, as I love scientific discussions about signaling molecules and receptor sites. There is nothing wrong, and a lot right about this method. However, we must not forget the equally important teleological approach, which  focuses on the emotional and spiritual aspects of health.  This mode involves the influence and consequences of the intertwined components we call thoughts, principles, personality traits, moods, or even Soul and Spirit.  There is no doubt that each individual is composed of different physical and non-physical aspects, and the goal of healing is to bring about an effective and balanced integration of these aspects.  To live one’s life in conflict, without tasting an integrative path with heart, is to live in sorrow. 

I have a story I’d like to share with you, about a breast cancer patient I treated.  She came to me, as so many others do, looking for herbs and vitamins to help her fight this disease.  During our initial conversations, I found out she was unhappy at her job as a schoolteacher, but found real happiness when singing for her church.  As I listened to her, an idea popped into my mind.  I wondered if she had ever thought of pursuing a gospel singing career.  She had thought about it, she said, and told me of her idea to create “teaching plays.” She would go to local schools, wearing the clothes of her great-grandmother who was born in 1863, and teach the students the history of American slavery through song.  I thought this was a wonderful idea and encouraged her strongly.  To make a long story short, she went ahead with her plan, and now she makes a living doing what she loves.  She is a minor “star” of sorts in our area, and schools from neighboring states are now booking her appearances years in advance.  By the way, her cancer disappeared after her first surgery, she breezed through chemotherapy using herbs, she discontinued Tamoxifen and all further treatment with Western medicines by choice after one year, and she has been cancer-free now since 1998.

NEVER FORGET - The Mind Controls the Body

ISHK's  Mind/Body Health Newsletter regularly publishes research examining the ways that the mind can directly affect health.  The following findings are some of my favorites:

•  Hostility toward one’s spouse elevates blood pressure and lowers immune response.

• People who regularly contribute their time and energy to help others are far less likely to die from all causes of disease than non-involved persons.

• Having a window in one’s office that affords a view of trees and flowers increases job satisfaction

• People who experience stress are six times more likely to become infected by a cold virus

• Having a pet decreases one’s chance of getting heart disease

Posted on Saturday, April 16, 2005 at 09:06AM by Registered Commenterposted by Dr. Tillotson in | Comments Off

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