Just in case you need more proof on neuroplasticity at any age.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=120549&CultureCode=en
“This study overturns decades-old beliefs that most of the brain is
hard-wired before a critical period that ends when one is a young
adult,” said MPFI neuroscientist Marcel Oberlaender, PhD, first author
on the paper. “By changing the nature of sensory experience, we were
able to demonstrate that the brain can rewire, even at an advanced age.
This may suggest that if one stops learning and experiencing new things
as one ages, a substantial amount of connections within the brain may be
lost.”
The researchers conducted their study by examining the brains of
older rats, focusing on an area of the brain known as the thalamus,
which processes and delivers information obtained from sensory organs to
the cerebral cortex. Connections between the thalamus and the cortex
have been thought to stop changing by early adulthood, but this was not
found to be the case in the rodents studied.
Being nocturnal animals, rats mainly rely on their whiskers as active
sensory organs to explore and navigate their environment. For this
reason, the whisker system is an ideal model for studying whether the
brain can be remodelled by changing sensory experience. By simply
trimming the whiskers, and preventing the rats from receiving this
important and frequent form of sensory input, the scientists sought to
determine whether extensive rewiring of the connections between the
thalamus and cortex would occur.
On examination, they found that the animals with trimmed whiskers had
altered axons, nerve fibres along which information is conveyed from
one neuron (nerve cell) to many others; those whose whiskers were not
trimmed had no axonal changes. Their findings were particularly striking
as the rats were considered relatively old – meaning that this rewiring
can still take place at an age not previously thought possible. Also
notable was that the rewiring happened rapidly – in as little as a few
days.
“We’ve shown that the structure of the rodent brain is in constant
flux, and that this rewiring is shaped by sensory experience and
interaction with the environment,” said Oberlaender. “These changes seem
to be life-long and may pertain to other sensory systems and species,
including people. Our findings open the possibility of new avenues of
research on development of the aging brain using quantitative anatomical
studies combined with noninvasive imaging technologies suitable for
humans, such as functional MRI (fMRI).”
The study was possible due to recent advances in high-resolution
imaging and reconstruction techniques, developed in part by Oberlaender
at MPFI. These novel methods enable researchers to automatically and
reliably trace the fine and complex branching patterns of individual
axons, with typical diameters less than a thousandth of a millimetre,
throughout the entire brain.
Oberlaender is part of the Max Planck Florida Institute’s Digital
Neuroanatomy group, led by Nobel laureate Bert Sakmann. The group
focuses on the functional anatomy of circuits in the cerebral cortex
that form the basis of simple behaviours (e.g. decision making). One of
the group’s most significant efforts is a program dedicated to obtaining
a three-dimensional map of the rodent brain. This work will provide
insight into the functional architecture of entire cortical areas, and
will lay the foundation for a mechanistic understanding of sensory
perception and behaviour.
http://www.mpg.de/5813329/rewiring_ageing_brain
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