TORONTO, Sept. 17, 2012 /CNW/ - Researchers from the Centre for
Addiction and Mental Health (CAMH) have identified a new role of a
chemical involved in controlling the genes underlying memory and
"The brain is a plastic tissue, and we know that learning and memory
require various genes to be expressed," says CAMH Senior Scientist Dr.
Art Petronis, who is a senior author on the new study. "Our research
has identified how the chemical 5-hmC may be involved in the epigenetic
processes allowing this plasticity." Dr. Petronis is head of the
Krembil Family Epigenetics Laboratory in CAMH's Campbell Family Mental
Health Research Institute.
5-hmC is an epigenetic modification of DNA, and was discovered in humans
and mice in 2009. DNA modifications are chemical changes to DNA. They
flag genes to be turned "on" - signalling the genome to make a protein
- or turned "off." As the overwhelming majority of cells in an
individual contain the same genetic code, this pattern of flags is what
allows a neuron to use the same genome as a blood or liver cell, but
create a completely different and specialized cellular environment.
The research, published online in Nature Structural & Molecular Biology, sheds light on the role of 5-hmC. Intriguingly, it is more abundant in
the brain than in other tissues in the body, for reasons not clear to
The CAMH team of scientists examined DNA from a variety of tissues,
including the mouse and human brain, and looked at where 5-hmC was
found in the genome. They detected that 5-hmC had a unique distribution
in the brain: it was highly enriched in genes related to the synapse,
the dynamic tips of brain cells. Growth and change in the synapse allow
different brain cells to "wire" together, which allows learning and
"This enrichment of 5-hmC in synapse-related genes suggests a role for
this epigenetic modification in learning and memory," says Dr.
The team further showed that 5-hmC had a special distribution even
within the gene. The code for one gene can be edited and "spliced" to
create several different proteins. Dr. Petronis found that 5-hmC is
located at "splice junctions," the points where the gene is cut before
"5-hmC may signal the cell's splicing machinery to generate the diverse
proteins that, in turn, give rise to the unprecedented complexity of
the brain," he says.
The research team is continuing to investigate the role of 5-hmC in more
detail, and to determine whether 5-hmC function is different in people
with bipolar disorder and schizophrenia compared to people without
This research was funded by the U.S National Institutes of Health, the
Canadian Institutes of Health Research, and the Tapscott Chair in
Schizophrenia Studies at the University of Toronto.
The Centre for Addiction and Mental Health (CAMH) is Canada's largest
mental health and addiction teaching hospital, as well as one of the
world's leading research centres in the area of addiction and mental
health. CAMH combines clinical care, research, education, policy
development and health promotion to help transform the lives of people
affected by mental health and addiction issues.
CAMH is fully affiliated with the University of Toronto, and is a Pan
American Health Organization/World Health Organization Collaborating
SOURCE: Centre for Addiction and Mental Health
For further information:
Media contact: Anita Dubey, Manager of Research Communications, CAMH; 416-535-8501 x 4932