Transcript The Revolution in Brain Science

The Revolution in Brain
Science
Neuroplasticity and
Neurogenesis
The Brain
The adult brain has long been considered
stable and unchanging, except for the
inevitable decline that occurs with aging.
This view is being challenged with clear
evidence that structural changes occur in
the brain throughout life, including the
generation of new neurons and other brain cells,
and connections between and among neurons.
Structural Changes
The structural changes seen in the brain
may be required to provide the extra
capacity we need for dealing with
complexity.
Structural Changes (Con’t)
It may also provide the underpinning for the
adaptability and flexibility, or plasticity that is
required for dealing with the variety of
challenges that we face throughout life.
Repair
Structural plasticity provides the mechanism
for the brain to repair itself. All organs of the
body have some capacity to repair
themselves following minor injury. Skin,
liver, heart, kidney, lung, and blood have
some level of repair capacity, and most have
the capacity to generate new cells to replace
damaged ones, at least to a small extent.
Early Dogma
Until recently, the brain was considered
unique in its lack of ability to repair itself
once it had matured to adulthood. “In the
adult center the nerve paths are something
fixed and immutable, nothing may be
regenerated” (S. Ramon y Cajal, 1928). In
general in was summed up as “try not to damage
your brain, because there is no way to fix it.”
Neuroplasticity
Neuro refers to the brain
Plasticity refers to the ability to change
itself, to change its structure and
function.
Neuroplasticity occurs in the brain
1 – At the beginning of life: when the
immature brain organizes itself.
2 – In case of brain injury: to compensate for
lost functions or maximize remaining
functions.
3 – Through adulthood: whenever something
new is learned and memorized
Neurogenesis
Neurogenesis means the production of new
neurons.
The observation that neurogenesis
continues in the adult brain has led to the
discovery that there are stem cells in the
adult brain that generate the new neurons.
Stem Cells
A stem cell is an uncommitted cell that,
when it divides, can give rise to any or all
the three main cell lineages of the brain:
neurons, astrocytes, and oligodendrocytes.
Where does cell genesis occur?
Neurogenesis, the process of generating
new neurons, does not occur in every part of
the brain. In fact, it only occurs in two areas:
the hippocampus (discovered in 1998) and
the olfactory bulb.
New neurons in the hippocampus seem
to help enhance learning and rebuild lost
memories.
Summary
The organization and layout of the nerve
cells in the human brain is truly remarkable.
The brain continues to change and adapt, as
well as repair itself, throughout life. The
brain follows an overall plan of development
but then alters based on experience,
stimulation, and the environment.
Brain Plasticity
Read and make summary notes from the
following website:
http://faculty.washington.edu/chudler/plast.html
1. What are the benefits of brain plasticity?
When is it not a benefit?
2. How could neurogenesis revolutionize the
treatment of an unhealthy brain?