Why Fetuses & Newborns Make Jerking Movements? Researchers Have the Answer
Researchers from the Mediterranean Institute of Neurobiology, Marseilles in collaboration with Dartmouth Neuroscience Center and Rutgers University, NJ, USA, shed a new light on the significance of spontaneous uncoordinated movements of the newborns and human fetuses.
(PRWEB) April 4, 2005 -- Everybody has the clear idea of the very special,
seemingly purposeless and unmotivated jerky movements of all newborns including
human babies. Pregnant women also are too familiar with similar movements inside
themselves when the unborn babies push, and kick, and roll. They do it almost
non-stop as soon as the pregnancy enters its second half. Scientists know that
the maturity of the second half of gestation human fetuses are equal to maturity
of newborn rat pups so they studied the newborn pups' movements to understand
how the human brain matures during pregnancy.
The common sense
explanation seems to be on the surface: both rat pups and human fetuses just
don't know how to move, haven't had time to learn yet. But is that it? Turns
out, Mother Nature knows better than that. The researchers figured out that
every single event of a pup's sudden limb or body twitches causes a closely
related important event in its brain. The matter is that immature brain of the
newborns (or fetuses) is pretty much a raw material. Though the neuronal
"hardware" is encoded already in the genes and exists by the time period we
discuss, it lies dormant and the neuronal networks posses only a very few
neuronal contacts (synapses) that are functional. The pups' environment is
pretty poor: they are blind and protected by the mothers from environmental
stimuli such as temperature, thirst, hunger, etc. The human fetuses environment
seems to be even more deprived.
What's left is up to the pups or human
fetuses themselves: they can move and send the stimuli from those movements into
the brain. It might be just occasional startles and muscle twitches, but every
single one of them leaves its mark on the brain in the form of special electric
activity of the brain's neurons. Mark by mark, a map of body's representation in
the brain is being created, the first orderly patterns in pups' brains. Later in
life, a detailed three-dimensional map will be completed where all senses will
find their target brain areas, but the first twitches are the only cause for the
very first functionally organized neuronal networks.
Without these
networks, there would be no coordinated, targeted, and finally well planned body
movements in the future. What's more, the process that begins with these
primitive movements, continues on to form neuronal network for every brain
function including perception and learning.
"If we compare the brain with
an orchestra, these early activities can serve a fine tuning of the participants
following by a rehearsal," said Rustem Khazipov, a team leader from Inmed -- the
Mediterranean Institute of Neurobiology, Marseilles.
The results of this
thought-provocking work were published in the Nature journal.
Further
information: http://inmednet.com/khazipov.htm
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Source : http://www.prweb.com/releases/2005/4/prweb224442.htm