Stem cells and adult neurogenesis

Stem cells and adult neurogenesis

November 4, 2019 5 By William Morgan


The brain is the most complex organ
of the human body.
It consists of numerous regions
working together
to provide various functions.
There are two regions of the adult brain,
the subventricular zone and
the hippocampus,
where stem cells multiply and
create new neurons.
This process, called adult neurogenesis,
has been shown to be
important in memory and learning.
The brain has a remarkable ability
to learn how to distinguish stimuli.
When two sensory stimuli are very similar
we’re unable to distinguish them at first.
But with repeated exposure,
we are able to separate
the different components
from each stimulus.
In our lab we study mice as they have
a highly developed sense of smell .
When receiving a sensory input,
thousands of receptor neurons
in the nasal cavity
send signals to the olfactory bulb.
The subventricular zone contains
stem cells that produce
30,000 new cells per day
that migrate to the olfactory bulb.
Once they arrive, the cells grow neurites
which then branch multiple times
to form mature olfactory neurons
with a complete tree-like structure.
We are able to specifically label
this population of neurons
by introducing DNA into the cells to
express a fluorescent protein.
We also express a special protein
that causes the cells
to be electrically active when
stimulated by light.
In our experiments,
the ability of mice to distinguish between
two odours is measured.
Mice with adult neurons labeled with
the light activating protein
learned faster when light stimulated
compared to the control group.
These results showed for the first time
a true gain of function
through adult neurogenesis.
We also study human loss of
adult neurogenesis function
in the hippocampus.
It has been linked to a
poor ability to distinguish between
scenes or episodes in one’s life
causing emotional confusion.
It is also associated with various
neurological conditions like
depression, anxiety and
post-traumatic stress disorder.
Stress, sleep deprivation and
the ageing process can cause a decrease
in neurogenesis.
Whereas adult neurogenesis
can be stimulated by
social interaction, exercise, and learning
it is the goal of our lab
to understand these mechanisms
and how to apply them to future therapies.