The Catskill Chronicle

By Mort Malkin

In the last B&B column we discussed the basic structural makeup of the body — the musculoskeletal system. Just five tissues: the bones, joints, muscles, tendons, and ligaments. Besides keeping us from jangling around like a skeleton at Halloween, the musculoskeletal system allows us to run & jump, lift small children, and play Beethoven’s Moonlight Sonata. We reviewed the various types of exercise and noted the benefits of aerobic exercise for cardiovascular health, carbohydrate metabolism, blood pressure, weight loss, the immune system, and brain chemistry stability.

Today, let’s be adventurous and look at one of the most complex disciplines in the Body & Brain discipline — brain chemistry. The billions of nerve cells in our brains, both gray and white, talk to each other constantly, even while we’re asleep. When an electrical impulse goes from one cell to another, it does so by means of one of several chemicals secreted into the spaces where the branches of the cells almost touch. In the brain, these chemicals are called neurotransmitters. Some of the chemicals are facilitators and some are inhibitors. A fine balance exists between agonist and antagonist effects. Given there are forty or more neuroactive chemicals in the brain, the combinations and permutations are pretty complex. You can do the math. The action of the neurotransmitters on their receptors are directly responsible for consciousness, thinking, and our various emotions, sensations, and movements. The principal actors are: acetyl choline, nor epinephrine, dopamine, serotonin, and GABA(gamma-amino butyric acid). Endorphins may best known among neurotransmitters, but their dampening of pain sensation and heightening of pleasure doesn’t occur 24/7 as some of the others do.

Acetyl choline is critical to memory and thought processing. In Alzheimer’s disease and in Creutzfeldt-Jacob disease, acetyl choline is in short supply. In cows, bovine spongiform encephalopathy can destroy cells that normally generate the neurotransmitter, and then the poor animal exhibits all the signs and symptoms of mad cow disease. Outside the brain, acetyl choline is released at the terminals where every motor nerve cell contacts the muscle cell it innervates. It is, as well, involved in our reflexes and many autonomic functions of the heart, lungs, and GI tract. It is our default neurotransmitter.

Norepinephrine maintains blood pressure. Proper concentrations keep our blood pressure in the Goldilocks range. It is also a general stimulant and keeps us in a good mood. In the body, norepinephrine inhibits gastrointestinal motility, relaxes the bronchioles, and constricts the blood vessels of the skin. It is good at multi-tasking.

Whereas acetyl choline is the major parasympathetic (rest and repair) neurotransmitter, norepinephrine is in charge of the sympathetic (fight or flight) half of the autonomic nervous system.

Dopamine influences the muscle tone of the body. In Parkinson’s disease, dopamine is in short supply and the individual cannot control muscle movements. Dopamine also gives a strong sense of well being and, thus, is an addiction chemical. It is increased by a variety of drugs both legal and illegal: nicotine, cocaine, heroin, and perhaps alcohol. A few studies reported in the sports medicine literature found that dopamine is also increased by aerobic exercise. That research was confirmed clinically  in several aerobic walking programs. After reaching adequate aerobic levels after six weeks, a dozen different smokers in separate wellness lifestyle groups were able to stop smoking with little or no withdrawal. It was only a small leap of imagination to connect the dots. Hey, American Cancer Society, listen up.

Serotonin is the antidepressant neurotransmitter. Low serotonin levels have been associated with clinical depression, impulsivity, and suicidal tendencies. Several brain centers and pathways are involved, and the complexities of the interactions are beyond our full comprehension. As you may assume, Big Pharma has developed many different drugs to treat depression and concomitant low serotonin levels. But, none of the drugs is a silver bullet. Side effects may be less beneficial for blood pressure, appetite & weight stability, and sexual function, among others. The goddess of unintended consequences is always at the ready.

GABA (gamma-amino butyric acid) is a less well known neurotransmitter. It has a wide range of inhibitory functions, especially at the hypothalamus which is generally considered the site of the emotions. Part of the way it says “cool it” is through the highest center of the brain, the prefrontal area of the cerebral cortex. A huge population was ready for GABA in pill form, and the drug companies rubbed their hands over the opportunity to exploit a waiting population. First, they gave a name to the short attention span of most children: ADD (attention deficit disorder). It was then broadened to ADHD by adding hyperactivity. A drug, Ritalin (methylphenidate), was quickly developed to treat the disorder. Finally, they educated teachers and parents, and the profits soared. Yes, there were a number of children who benefitted; but mostly, kids are just kids and need their attention riveted by the lessons and activities of school and home.

The forty or more neuroactive chemicals are creatively combined and broken down in our bodies and brains continuously. They are in constant interaction, even when we’re watching TV. The balance changes with our needs as we go about our ordinary and more demanding activities. The best we can do is to live a healthy lifestyle, not too much of any of the components and not too little. Hippocrates had it about right in the fifth century BCE. Here’s to mental health.