From: "Mike Lorrey" <firstname.lastname@example.org>
> This must be why neurosuspension hasn't caught on widely: the 'feeling'
> masses are being justifiably told by their more dominant brain that it
> doesn't want to be left behind...
No, not at all. The enteric nervous system is not "dominant," the reason you
don't want to be uploaded without your enteric nervous system (ENS) is that
your ENS contains hundreds of millions of neurons which interact with the rest
of the CNS (central nervous system) to form the complete neurological
structure that is you.
The Second Brain : The Scientific Basis of Gut Instinct and a Groundbreaking
New Understanding of Nervous Disorders of the Stomach and Intestines
Did you ever tell someone that they think with their stomach? Then you're on
the cutting edge of scientific thought, according to researcher Michael D.
Gershon. The title of his book The Second Brain refers to the hundred million
nerve cells in and around our guts that often act entirely independently of
the dictator inside our heads. This isn't so bad--there are some meals we'd
rather not have to think about eating, much less digesting. Gershon tells us
the stories of his development into a scientist, his determination to promote
neurogastroenterology as a legitimate field of research, and the nature of
"the brain gone south," all with humor and aplomb.
Though not for the overly squeamish (after all, even if Gershon were to pull
his punches, his subject still carries traces of old taboos), The Second Brain
is a lively and invigorating read. The illustrations are superb and well
labeled; this complements the text, which ranges from clinical to personal, as
when the author details the events leading to his mother's tragic death
following unnecessary surgery for an ulcer. The interactions between the
enteric nervous system and digestion, emotion, and disease are not simple, but
Gershon's patient prose explains everything in terms any interested layperson
As in the best scientific works, The Second Brain informs and inspires,
surprising the reader with unexpected complexities and mysteries arising in
such a seemingly primitive venue. It makes excellent after-dinner
reading. --Rob Lightner
Jacqueline Boone, The New York Times Book Review
In ,"The Second Brain, Gershon makes a persuasive, impassioned and, at times,
downright lyrical case...the book succeeds in presenting an often grim and
complex topic in a surprisingly witty and engaging manner"
Wyoming researcher studies 'second brain' in gut tissues
When we eat a meal, we're generally confident that our bodies will process the
fuel efficiently and naturally. After all, it's been happening continuously
since the day we were born. But what is it really that we are placing our
"It used to be thought that this is a simple system to study, but there are as
many neurons in the gut as there are in the spinal cord," Wade said.
According to Gershon, this system is also critical for our emotional
Enteric nervous system
The enteric nervous system is made up of two plexuses, or networks of neurons,
embedded in the wall of the gastrointestinal tract. The outermost collection,
lying between the inner circular and outer longitudinal smooth-muscle layers
of the gut, is called the myenteric (or Auerbach's) plexus. Neurons of this
plexus regulate the peristaltic waves, consisting of polarized muscular
activity, that move digestive products from oral to anal openings. In
addition, myenteric neurons control local muscular contractions that are
responsible for stationary mixing and churning. The innermost group of neurons
is called the submucosal (or Meissner's) plexus. This group regulates the
configuration of the luminal surface, controls glandular secretions, alters
electrolyte and water transport, and regulates local blood flow.
Three functional classes of intrinsic enteric neurons are recognized: sensory
neurons, interneurons, and motor neurons. Sensory neurons, activated by either
mechanical or chemical stimulation of the innermost surface of the gut,
transmit information to interneurons located within the myenteric and
submucosal plexi, and the interneurons relay the information to motor neurons.
Motor neurons in turn modulate the activity of a variety of target cells,
including mucous glands, smooth muscle cells, endocrine cells, epithelial
cells, and blood vessels.
Extrinsic neural pathways also are involved in the control of gastrointestinal
functions. Three types exist: intestinofugal, sensory, and motor.
Intestinofugal neurons reside in the gut wall; they send their axons to the
preaortic sympathetic ganglia and control reflex arcs that involve large
portions of the gastrointestinal tract. Sensory neurons relay information
regarding distention (pain) and acidity into the central nervous system. There
are two types of sensory neurons: sympathetic neurons, which originate from
dorsal-root ganglia found at the thoracic and lumbar levels; and
parasympathetic neurons, which originate in the nodose ganglion of the tenth
cranial nerve (vagus) or in dorsal-root ganglia at sacral levels S2-S4. The
former innervate the entire gastrointestinal tract from the pharynx to the
left colic flexure, and the latter innervate the distal colon and rectum. Each
portion of the gastrointestinal tract receives a dual sensory innervation:
pain sensations travel via sympathetic afferents, and sensations that signal
information regarding the chemical milieu of the gut travel by way of
parasympathetic fibres and are not consciously perceived.
The third extrinsic pathway, exercising motor control over the gut, arises
from parasympathetic preganglionic neurons found in the dorsal vagal nucleus
of the medulla and from sympathetic preganglionic neurons in the lateral horns
of the spinal cord. These outflows provide modulatory commands to the
intrinsic enteric motor system and are nonessential in that basic functions
can be maintained in their absence.
Through the pathways described above, the parasympathetic system activates
digestive processes while the sympathetic system inhibits them. The
sympathetic system inhibits digestive processes by two mechanisms: (1)
contraction of circular smooth muscle sphincters located in the distal portion
of the stomach (pyloric sphincter), small intestine (ileo-cecal sphincter),
and rectum (internal anal sphincter), which act as valves to prevent the
oral-to-anal passage (as well as reverse passage) of digestive products; and
(2) inhibition of motor neurons throughout the length of the gut. In contrast,
the parasympathetic system provides messages only to myenteric motor neurons.
For those who missed it the first time posted:
Two brains are better than one, especially if you're hungry
the enteric nervous system
The Enteric Nervous System:
A Second Brain
Useless hypotheses, etc.:
consciousness, phlogiston, philosophy, vitalism, mind, free will, qualia,
analog computing, cultural relativism, GAC, CYC, and ELIZA
Everything that can happen has already happened, not just once,
but an infinite number of times, and will continue to do so forever.
(Everything that can happen = more than anyone can imagine.)
We won't move into a better future until we debunk religiosity, the most
regressive force now operating in society.
This archive was generated by hypermail 2b30 : Fri Oct 12 2001 - 14:39:50 MDT