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Title: How a Chorus of Synchronized Frequencies Helps You Digest Your Food

Link: https://science.slashdot.org/story/25/10/31/0...

alternative_right shares a report from Phys.org: It is known in the
scientific community that if you have a self-sustained oscillation, such as
an arteriole, and you add an external stimulus at a similar but not identical
frequency, you can lock the two, meaning you can shift the frequency of the
oscillator to that of the external stimulus. In fact, it has been shown that
if you connect two clocks, they will eventually synchronize their ticking.
Distinguished Professor of Physics and Neurobiology David Kleinfeld found
that if he applied an external stimulus to a neuron, the entire vasculature
would lock at the same frequency. However, if he stimulated two sets of
neurons at two different frequencies, something unexpected happened: some
arterioles would lock at one frequency and others would lock at another
frequency, forming a staircase effect. Searching for an explanation,
Kleinfeld enlisted the help of his colleague, Professor of Physics Massimo
Vergassola, who specializes in understanding the physics of living systems,
and then recruited Ecole Normale Superieure graduate student Marie Sellier-
Prono and Senior Researcher at the Institute for Complex Systems Massimo
Cencini. Together, the researchers found they could use a classical model of
coupled oscillators with an intestinal twist. The gut oscillates naturally
due to peristalsis -- the contracting and relaxing of muscles in the
digestive tract -- and provided a simplified model over the complex network
of blood vessels in the brain. The intestine is unidirectional, meaning
frequencies shift in one direction in a gradient from higher to lower. This
is what enables food to move in one direction from the beginning of the small
intestine to the end of the large intestine. "Coupled oscillators talk to
each other and each section of the intestine is an oscillator that talks to
the other sections near it," stated Vergassola. "Normally, coupled
oscillators are studied in a homogeneous setting, meaning all the oscillators
are at more or less similar frequencies. In our case, the oscillators were
more varied, just as in the intestine and the brain." In studying the coupled
oscillators in the gut, past researchers observed that there is indeed a
staircase effect where similar frequencies lock onto those around it,
allowing for the rhythmic movement of food through the digestive tract. But
the height of the rises or breaks, the length of the stair runs or
frequencies, and the conditions under which the staircase phenomenon occurred
-- essential features of biological systems -- was something which had not
been determined until now. The findings have been published in the journal
Physical Review Letters.

Read more of this story at Slashdot.

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