Through using a high resolution MRI to study myelin sheaths, an
insulator around the brain's wiring, researchers found that the
brain connections developed later in life were the first to deteriorate.
Researchers are hoping to use these results to further examine how
lifestyle plays a part in brain aging and then come up with a medication
that would delay the aging process or work as a preventative to
Alzheimer's.
This study sheds some light on the role of myelin in brain development
and degeneration. The study also stresses the importance of using
this type of MRI to study the relationship between aging and Alzheimer's
disease.
Myelin is defined as a layer of fat that contains a substantial
amount of cholesterol, which enables it to wrap tightly around axons
rapidly sending messages through the brain by insulating the brain
connections. Production of myelin is churned out in greater amounts
as the brain ages and continues to grow into adulthood. This process
results in increased cholesterol levels, which eventually lead to
production of a toxic protein that works with other toxins in attacking
the brain.
The production of all these toxins soon begin to alter the brain
connections and at a certain point results in the creation of destructive
plaques. The formation of plaque then start to disrupt the brain
connections developed in the later years in the cortex of people
with Alzheimer's disease.
Researchers compared the functioning of the brain to the Internet
and explained that the brain's processing speed and quality is dependant
on how well it is able to process information. The performances
of these functions, for the most part, are dependent on the insulation
of the brain's wiring. Similar to the Internet, as we grow older,
the myelin insulation becomes weaker and leads to a gradual slowing
down of the speed and quality of our internal Internet.
Researchers claimed that this MRI could be used to identify specific
deteriorating areas of the myelin sheath surrounding the brain.
As part of the study, researchers studied how the deterioration
of myelin affected two areas of the brain, the splenium and genu
regions. The splenium region is responsible for early brain development
essential to vision. The genu on the other hand, centered on more
complex brain connections that developed later in life such as decision
making, memory and impulse control.
Conclusions From the Study
- The brain connections in the genu region degenerated three times
as fast as the spenium region
- Deterioration of myelin is much more prevalent in Alzheimer's
patients than in healthy elderly adults
- The breakdown of myelin is a strong contributor to the development
of Alzheimer's
EurekAlert
July 12, 2004
| 