Gut Instincts & your second Brain

When it comes to your moods, decisions and behaviour, the brain in your head is not the only one doing the thinking

IT’S been a tough morning. You were late for work, missed a crucial meeting and now your boss is mad at you. Come lunchtime you walk straight past the salad bar and head for the stodge. You can’t help yourself – at times of stress the brain encourages us to seek out comfort foods. That much is well known. What you probably don’t know, though, is that the real culprit may not be the brain in your skull but your other brain.

Yes, that’s right, your other brain. Your body contains a separate nervous system that is so complex it has been dubbed the second brain. It comprises an estimated 500 million neurons – about five times as many as in the brain of a rat – and is around 9 metres long, stretching from your oesophagus to your anus. It is this brain that could be responsible for your craving under stress for crisps, chocolate and cookies.

Embedded in the wall of the gut, the enteric nervous system (ENS) has long been known to control digestion. Now it seems it also plays an important role in our physical and mental well-being. It can work both independently of and in conjunction with the brain in your head and, although you are not conscious of your gut “thinking”, the ENS helps you sense environmental threats, and then influences your response. “A lot of the information that the gut sends to the brain affects well-being, and doesn’t even come to consciousness,” says Michael Gershon at Columbia-Presbyterian Medical Center, New York.

The Brains Drain System

The brain drain is real. There is a network of previously unrecognised vessels that rid the brain of unwanted extracellular fluids and other substances, including amyloid-beta – a peptide that accumulates in the brain of people with Alzheimer’s. The new discovery looks set to add to our understanding of the disease.

Jeffrey Iliff at the University of Rochester Medical Centre, New York, and his colleagues, were intrigued by the fact that there are no obvious lymphatic vessels in the brain. Among other things, the lymphatic system removes waste interstitial fluids from body tissue.

“It seemed strange that such an important and active organ wouldn’t have a specialised waste-removal system,” says Iliff.

When the researchers added fluorescent and radioactive tracers to the cerebrospinal fluid of live mice, the tracers quickly spread throughout the rodents’ brains. Using two-photon microscopy to visualise the movement in real-time, the team saw cerebrospinal fluid permeating the entire brain through ‘pipes’ surrounding blood vessels, similar to the lymphatic system that services all other organs.

The pipes work on hydraulic principles, though, and so the system breaks upon opening, making it hard to identify it outside living organisms.

Acupuncture studies by NCCAM

Introduction

Physical pain is a common occurrence for many People; in fact, a national survey found that more than one-quarter of U.S. adults had recently experienced some sort of pain lasting more than a day. In addition to conventional treatments, such as over-the-counter and prescription medications, people may try Acupuncture in an effort to relieve pain. This fact sheet provides basic information about pain and acupuncture, summarizes scientific research on acupuncture for specific kinds of pain, and suggests sources for additional information.

Key Points

• People use acupuncture for various types of pain. Back pain is the most commonly reported use, followed by joint pain, neck pain, and headache.
• Acupuncture is being studied for its efficacy in alleviating many kinds of pain. There are promising findings in some conditions, such as chronic low-back pain and osteoarthritis of the knee; but, for most other conditions, additional research is needed. The National Center for Complementary and Alternative Medicine (NCCAM) sponsors a wide range of acupuncture research.
• Acupuncture is generally considered safe when performed correctly.
• In traditional Chinese medicine theory, acupuncture regulates the flow of qi (vital energy) through the body. Research to test scientific theories about how acupuncture might work to relieve pain is under way.

Why stress gets on your nerves

MOST PEOPLE would agree that certain events in their life, such as bereavement, changing jobs, examinations, or even rush-hour travel in big cities, are stressful. We try to avoid stress, but if we cannot, we must try to adapt to it. This adaptation is sometimes referred to as ‘toughening up’. Although stress is difficult to define, we know that both avoidance and toughening up are crucial ways of coping with it.

When we cannot cope, stress can lead to irritability and fatigue, and other more serious disorders, such as gastric ulcers, cardiovascular disease, anxiety and depression. Yet not everyone subjected to severe stress suffers from a heart attack or a bout of depression: some individuals are much more vulnerable than others. Many neuroscientists now suspect that the difference in the ability to cope may lie in biochemical changes in the brain involved in the process of adaptation to stress.