It's no coincidence those who suffer from lack of sleep (insomnia)
often struggle with obesity as well. Research has found that the
less people sleep, the more likely they are to gain weight, as the
lack of sleep triggers hormone imbalances that boost the desire
to eat.
In a study involving mice and human cells, researchers traced the
link between sleep debt and obesity to the hypocretin/orexin cells
in the hypothalamus region of the brain -- which includes vital
autonomic regulatory centers (as for the control of food intake)
-- that are easily excited and sensitive to stress. These specialized
brain cells are particularly vulnerable to over-stimulation and
lack the ability of most other neurons to filter out signals from
other regions of the brain that aren't meant for them.
What does this mean? If the hypocretin/orexin
cells are over-stimulated by either environmental or mental stress
in daily situations, they may support sustained arousal, generating
sleeplessness and leading to overeating.
Finding ways to moderate this wiring may aid researchers in discovering
new treatment methods for insomnia and other sleep disorders.
Revealing the Link
Researchers conducted experiments using lab mice and human brain
slices to study how the cells are organized and connected to the
rest of the brain. They found:
- Each brain cell has 10 times
more nerve junctions that excite them than inhibitory contacts,
with humans and mice.
- Overnight food deprivation encouraged the formation of even
more "excitatory" inputs.
- Once the mice were fed, the inputs reversed, showing the responsiveness
of the hypocretin system to current conditions.
Therefore, those suffering from weight and sleep problems would
benefit from reducing stressful aspects in their lives.
Cell
Metabolism April 2005, Volume 1, Issue 4: 279-286
Medical
News Today April 12, 2005
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