news
Under pressure
Scientists make leap in
understanding how blood
pressure affects the brain.
S
cientists have made a breakthrough
in understanding the way the brain’s
blood flow affects certain serious
illnesses such as high blood pressure,
migraines and even dementia.
The academics from the University of
Auckland, University College London and
Bristol University have discovered that the
brain has its own blood pressure sensors
that monitor and regulate its blood flow,
separate from the body-wide blood
pressure control system.
The brain needs more blood than any
other organ, and disturbances to brain
blood flow are a known cause in many
diseases. For example, sustained reduction
in brain blood flow is said to be a likely
cause of cognitive decline, dementia
and neurodegenerative disease, such as
Alzheimer’s disease.
In the researchers’ animal study, they
found that the sensors – tiny cells called
astrocytes – strategically squeezed
between blood vessels and nerve cells
in rats’ brains. When the researchers
stimulated these cells, they increased
blood flow into the brain.
“These astrocyte cells are exquisitely
sensitive to reductions in brain blood
flow,” said Professor Julian Paton from the
University of Auckland’s Faculty of Medical
and Health Sciences. “When blood supply
‘Tsunami’ warning
Call for national audit
into malnutrition.
T
6
he Dietitians Association of
Australia (DAA) is calling for a
national audit into malnutrition
agedcareinsite.com.au
in aged care to gauge the true extent of
the problem and understand the needs of
affected aged care residents.
DAA chief executive Robert Hunt
said data presented to the aged care
royal commission last year suggested
is reduced, they release a chemical signal
to nearby nerve cells that raise blood
pressure, restoring blood flow to the brain.
“What we have discovered is that the
brain has an automatic way to make sure
that brain blood flow is preserved.
“Unfortunately, in pathological
conditions, this is happening at the
expense of generating higher blood
pressure in the rest of the body.”
The researchers say this breakthrough
could have serious implications for how we
treat these diseases.
Professor Alexander Gourine from
University College London said: “We are
very excited about this discovery. There has
never been a formal description of a blood
flow or blood pressure sensor within the
brain before.
“Our new data identify astrocytes as
brain blood flow sensors that are critically
important for setting the normal level of
systemic (arterial) blood pressure, and in
doing so ensures that the brain receives a
sufficient amount of oxygen and nutrients
to support the uninterrupted operation of
the information processing machinery.” ■
malnutrition (or the risk of malnutrition)
was evident in half of all residents.
Hunt suggested this snapshot is likely to
be the “tip of the iceberg” and pushed for
urgent attention to be given to the problem
now, pointing out that there is no routine
assessment of malnutrition for aged
care residents.
“We cannot afford to wait until the
recommendations in the final report
from the commission are handed down
in November – by then, many at-risk
residents will have become malnourished,”
he said.
“These figures should act as a tsunami
warning, and without action we will soon
be overrun with the economic, social and
health costs as malnutrition progresses.”
The DAA said carrying out a national
aged care malnutrition audit is a cost-
efficient measure that would enable the
government to create the policies and
actions needed to deal with the problem,
while also identifying those who need
immediate intervention.
It also argued that dietitians can lead
the way in providing improved nutrition
to ensure a better quality of life for aged
care residents.
“I urge the government to act now,
to address the critical issues concerning
older Australians,” Hunt said. ■