photo credit: Andre Um
The word neuropeptide is so new thai it’s rare to find it in a dictionary published before 1990. I have a 1987 copy of the Australian Concise Oxford Dictionary and the word neuropeptide doesn’t get a guernsey, although the word peptide is discreetly tucked away in the pages containing words that begin with the letter “P”. I have access to 225,000 words in a beautifully bound two volume set of The World Book Dictionary hut alas neuropeptide is nowhere to be found. There’s neuroblast, neurodermatitis, neuroendocrinology and neuropter which should not be thought of as a helicopter with a human brain.
Over the past 25 years spectacular advances have been made in the field of brain research. One of the landmark discoveries took place in 1973 when Dr. Solomon Snyder, a neuroscientist working at the John Hopkins University, made a remarkable discovery that the brain had its own natural opiate-like receptors (Pert & Snyder, 1973).
It was assumed that these receptors were the sites in the brain where opiates such as morphine and heroin acted to produce pleasure and the relief of pain.
Snyder and his colleague, Dr. Candice Pert, concluded that if the brain had opiate receptors then it also had its own natural opiates. His remarkable discovery led to the establishment of a new branch of science called molecular psychology.
[Molecular psychology is based on evidence that human thought, emotion and behaviour results from the interplay of chemical molecules across the surface of brain cells.]
The work of Snyder and other neuroscientists has revolutionised our
understanding of how the brain works and has had enormous flow-on
benefits in the fields of psychiatric medicine.
Neuropeptides and stress
Neuropeptides are naturally occurring substances found in the brain. They are also found in the intestine where they regulate the flow of food by altering the rhythm of contractions.
When we are under stress neuropeptide levels increase to protect the immune system, the body’s front line of defence against disease.
Generally speaking, neuropeptides are involved in many functions of the brain associated with pleasure and pain. A neuropeptide called dynorphin was discovered in 1979.
The word dynorphin means power and this is appropriate because dynorphin is 200 times more powerful in its actions than morphine.
Neuropeptides are being discovered all the time. At least sixty have been indentified so far and they rally under such fancy names as alpha endorphin; gamma-endorphin; beta endorphin; leu-enkephalin; met-enkephalin; Peptide E; Substance P. The best known neuropeptides are endorphin (not to be confused with the Australian rock band of the same name) and enkephalin. The word endorphin is a shorthand expression covering all the natural opiates produced by the body.
Spiders and monkeys have endorphins!
Endorphins are found it many other organisms besides humans. These powerful neuropeptides are present in the humble, but persistent leech; in a wide range of spiders; in monkeys swinging from tree to tree; in rats that scuffle in the night; and abundantly present in lobsters … especially those that are swimming indifferently in illuminated fish tanks in Seafood Restaurants!.
Endorphin and enkephalin are found in high concentrations in the limbic system, particularly in those areas related to pleasure and pain.
Certain parts of the brain contain dense clusters of receptors for neuropeptides. In X-rays of the brain they show up like dense galaxies of stars in a vast universe.
Neuropeptides serve many useful functions. During stress they are released to help us cope with the pain. This is probably why people who suffer severe injuries in a car accident don’t feel the full pain wave until they get to hospital. The brain has it own morphine and it uses it in times of emergency.
Shirley MacLaine talks about neuropeptides.
Actress Shirley MacLaine relates a personal incident that demonstrates the power of the body’s neuropeptides to suppress pain:
“It was the evening of the Cinderella performance. I was dancing the Fairy Godmother, and I stood in the wings after completing my plies and warming up exercises. The orchestra tuned up, the house lights dimmed, and the audience quieted. The overture began and the curtain was about to open. Before it did, I took a few practise grand jetés across the stage.
Snap!
I went down. A sharp pain pierced my right ankle and it doubled under me. Terrified, I looked quickly around to see if anyone had noticed. No one had. Dancers fall down all the time. I looked at the ankle. It was already swollen. I tightened my toe-shoe ribbon to a death grip, and stood up. The curtain went up.
I climbed on point and began to dance. With each movement I seemed to step further out of myself. The pain left me. I began to feel a sense of triumph that gave me strength – not an anesthetized strength as though I had dulled the pain, but more as though my mind had risen above me and was looking down. The dance movements came in an easy flow, and I felt that I was soaring above myself. I knew the pain was there, but I was on top of it somehow. It was probably my first experience in mind over matter. And the feeling was exquitite.
On a ballet stage in Washington, D.C., I first came in contact with my potential talent for becoming a mystic!
Two and a half hours later the ballet and curtains call were over. I asked for an ambulance and then the pain hit. I didn’t walk for four months.” (MacLaine 1970, p.12)
Neuropeptides stop us feeling like a drug addict in a state of withdrawal.
Without neuropeptides we would suffer constant wracking pain from head to toe feeling like the drug addict in a state of withdrawal. When the addict is hitting his brain with heroin, the brain lowers production of the endorphins and enkephalins. When the heroin is removed withdrawal sets in as the body tries to fight pain without its natural opiates.
Valium has been used for decades to relieve pain. It does this by stimulating the production of more endorphins. Enkephalin is known to be a natural pain-killer.
When are neuropeptides active in the body and why are they important to you?.
Neuropeptide levels are known to be high in long-distance runners. Their presence is certainly detectable during sexual orgasm. They’re the nice feelings that accompany being in love. Evidence has been produced to show that they play an active role in the positive outcomes associated with acupuncture and the placebo effect.
Their release is often triggered when we are being praised or complemented. If you meet a client who shows genuine enthusiasm to see you again and compliments you on your excellent service then the flush of good feeling that follows from this praise is a sign that the neuropeptides are at work.
The Body’s Sixth Sense.
Recent research suggests that neuropeptides have a positive effect on the body and play a key role in health and well-being. While it was once thought that communication between the brain and the body was a one- way street with the brain sending out instructions and the body responding, scientists are now finding evidence showing that the conversation is two way. The key messengers in this biological dialogue are the neuropeptides. They have even been dubbed the body’s sixth sense because they can alert us to problems even before we get sick.
Neuroscientist Dr. Candice Pert has proposed that our emotions are produced as a result of the interplay of neuropeptides in the brain and in the body. She has suggested that “…such biochemically mediated emotional patterns may have served during our evolutionary history by biasing the way that we think and behave so as to increase our chances of survival, both as individuals and as a species.” (Wood & Dienstfrey 1989, p.38)
lt seems possible that our desire to be healthy and productive may actually encourage the neuropeptides in their work. People who are high achievers and who enjoy their work experience the neuropeptide good feelings quite regularly. Those feelings actively promote a positive sense of well-being.
On an organizational level this equates to that tangible (hut difficult to describe) good atmosphere of a positive, team-based environment. Each person in the team, from the manager to the most junior assistant, benefits from increased neuropeptide activity and the accompanying highs which lead to better productivity.
Neuropeptides and addiction.
Some people are unable to produce enough neuropeptides to meet the demands of the body. Pharmacologists are now speculating that lower- than-normal levels of neuropeptides may cause the psychic-pain that drives people to turn to alcohol just to feel normal.
Enkephalins and endorphins are very powerful neurotransmitters. So powerful in fact that it is possible to become self-addicted! Experiments with rats demonstrate this phenomena. Animals given an opportunity to electrically stimulate the pleasure centres in their brain by pressing a lever have been seen to stimulate themselves for 24 hours without rest and as often as 5,000 times an hour! This is why addicts are prepared to sell their grandmother for another fix.
One way to demonstrate the power of neuropeptides is to see what happens when their receptors are blocked.
By some strange twist of nature the molecules of the opium poppy happen to fit into the receptor key locks reserved for the brain’s natural opiates, endorphin and enkephahin.
This is why heroin has such a powerful effect on mood. Once heroin gets into the brain the molecules go straight to the receptors reserved for the endorphin and enkephalins and a massive high results. The heroin switches on the body’s pleasure centres in a way that nature never intended.
lf a person is delivered to a casually ward in a hospital in a comatose state and the intern suspects heroin overdose then she has one very effective way of confirming the diagnosis. She injects the patient with a synthetic neurotransmitter called Naloxone. If the coma is heroin induced then the patient soon sits up but feels like a thousand hangovers.
Naloxone works by locking onto the receptor sites that heroin is working over. It sits in the lock but doesn’t activate the neuron. It’s like trying to start your Ford with your next door neighbour’s Ford key. The key will sit nicely in the ignition lock but it won’t switch on the motor. Naloxone does just that. It blocks the heroin. The addict regains consciousness but because the good feeling key holes are all blocked he feels exceptionally unwell.
The take away message from this post is that our brain has been marvelously designed through years of natural selection and that it will works wonders for us if we treat it with respect.
References:
MacLaine, S. (1970). Don’t Fall Off the Mountain. New York. Bantum Books.
Pert, C.B., & Snyder, S.H. (1973) Opiate Receptor: Demonstration in Nervous Tissue. Science , 179, 101 1-101
Wood, C & Dienstfrey, H. (1989) Positive Emotions and Health: A Conference Report. Advances, 6, 2:36-42.
