This was in today's newspaper.
 
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'GUT FEELINGS' STEM FROM 2ND BRAIN, SCIENTISTS SAY
By SANDRA BLAKESLEE
New York Times, January 23, 1996
 
Ever wonder why people get "butterflies" in the stomach before going on
stage? Or why an impending job interview can cause an attack of intestinal
cramps?
 
And why do antidepressants targeted for the brain cause nausea or abdominal
upset in millions of people who take such drugs?
 
The reason for these common experiences, scientists say, is because each of
us literally has two brains _ the familiar one encased in our skulls and a
lesser known but vitally important one found in the human gut. Like Siamese
twins, the two brains are interconnected; when one gets upset, the other
does, too.
 
The gut's brain, known as the enteric nervous system, is located in sheaths
of tissue lining the esophagus, stomach, small intestine and colon.
Considered a single entity, it is packed with neurons, neurotransmitters and
proteins that zap messages between neurons, support cells like those found in
the brain proper, and a complex circuitry that enables it to act
independently, learn, remember and, as the saying goes, produce gut feelings.
 
The brain in the gut plays a major role in human happiness and misery. But
few people know it exists, said Dr. Michael Gershon, a professor of anatomy
and cell biology at Columbia-Presbyterian Medical Center in New York.
 
For years, people who had ulcers, problems swallowing or chronic abdominal
pain were told their problems were imaginary, emotional, simply all in their
heads, Gershon said. They were shuttled to psychiatrists for treatment.
 
Doctors were right in ascribing these problems to the brain, Gershon said,
but they blamed the wrong one. Many gastrointestinal disorders like colitis
and irritable bowel syndrome originate from problems within the gut's brain,
he said.
 
And the current wisdom is that most ulcers are caused by a bacterium, not by
hidden anger at one's mother.
 
Symptoms stemming from the two brains get confused, Gershon said. "Just as
the brain can upset the gut, the gut can also upset the brain. If you were
chained to the toilet with cramps, you'd be upset, too," he said.
 
Details of how the enteric nervous system mirrors the central nervous system
have been emerging in recent years, said Gershon, who is considered one of
the founders of a new field of medicine called neurogastro-enterology.
 
Nearly every substance that helps run and control the brain has turned up in
the gut, Gershon said.
 
Major neurotransmitters like serotonin, dopamine, glutamate, norepinephrine
and  nitric oxide are there. Two dozen small brain proteins, called
neuropeptides, are in the gut, as are major cells of the immune system.
 
Enkephalins, one class of the body's natural opiates, are in the gut. And in
a finding that stumps researchers, the gut is a rich source of
benzodiazepines _ the family of psychoactive chemicals that includes such
ever-popular drugs as Valium and Xanax.
 
In evolutionary terms, it makes sense that the body has two brains, said Dr.
David Wlngate, a professor of gastrointestinal science at the University of
London and a consultant at Royal London Hospital.
 
The first nervous systems were in tubular animals that stuck to rocks and
waited for food to pass by, Wingate said. The limbic system is often referred
to as the "reptile brain."
 
As life evolved, animals needed a more complex brain for finding food and
sex, and so developed a central nervous system.
 
But the gut's nervous system was too important to put inside the newborn head
with long connections going down to the body, Wingate said. Offspring need to
eat and digest food at birth.
 
Therefore, nature seems to have preserved the enteric nervous system as an
independent circuit inside higher animals. It is only loosely connected to
the central nervous system and can mostly function alone, without
instructions from topside.
 
END
 
Regards,
Alan Bonander