DBS mice (S) spent a greater amount of time (indicated in
red) swimming near a submerged landing (dotted circle) compared
with non-stimulated mice (NS) indicating improvements in spatial
learning (Image: Reprinted with permission: Stone, et al. The
Journal of Neuroscience 2011)
With the possible exception of those affected by
hyperthylmesia - a rare condition where a person has an
extraordinary capability to recall events from their past - most
of us wouldn't mind having our memory enhanced. That's just what
appears to have happened to a group of mice when targeted areas
of their brains were electrically stimulated. The treatment
triggered an increase in the creation of new cells in the
hippocampus, with experiment results suggesting the mice's
spatial learning improved. The researchers responsible say the
results could have implications for the treatment of memory
disorders in humans.
A clinical treatment known as deep brain stimulation (DBS),
which delivers electrical pulses to targeted areas of the brain,
has been used with some success in the treatment of movement and
affective disorders, such as Parkinson's disease, and has also
been recently explored for treatment of a range of neurologic
and psychiatric conditions, including major depression and
Tourette syndrome. The findings of this new study led by Paul
Frankland, PhD, of
The Hospital
for Sick Children (SickKids), suggests the treatment could
also have applications for memory disorders.
Throughout our lives, new cells are born in parts of the
hippocampus - an area of the brain that plays important roles in
spatial navigation and the consolidation of information from
short-term to long-term memory. It is one of the first regions
of the brain to suffer damage in Alzheimer's disease, with
memory problems and disorientation among the first symptoms.
Frankland and his colleagues found that subjecting the
entorhinal cortex - a region of the brain that directly
communicates with the hippocampus - of adult mice to one hour of
electrical stimulation led to a two-fold increase in new cells
in the hippocampus. Although the burst of new cells lasted for
only about one week, the cells produced during this time
developed normally and made connections with nearby brain cells.
To test whether the newly integrated cells produced changes
in memory, six weeks later the researchers tested how well the
mice learned to navigate onto a landing submerged in a small
pool of water. Compared with mice that didn't receive the
therapy, the DBS-treated mice spent more time swimming near the
landing, which the researchers say suggests improved spatial
learning.
The results of the study echo
a previous study that saw patients receive a boost in math
skills lasting up to six months after an electrical current was
applied to their parietal lobe - a region of the brain crucial
for numerical understanding.
The findings of this new DBS study are published in the
September 21 issue of
The Journal
of Neuroscience.
Copyright © gizmag 2003 - 2011 To subscribe or visit go to:
http://www.gizmag.com