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Area deep in the brain generates activity
related to consciousness and dreaming.
Background. When we are awake with our eyes closed, electrodes on
the scalp measure waves of human brain activity at 10 Hertz, or 10 per
second. If we fall asleep, these waves slow to 6-8 Hertz during
drowsiness and light sleep, and then to 2-4 Hertz in deep sleep. When
we open our eyes, are alerted and pay attention, our brains begin to
fire at 20-40 Hertz. These waves are called 'gamma band activity', and
are present during consciousness and learning, and also during
dreaming. Dogma was that 'gamma band activity' was only present in the
cerebral cortex, the thin, convoluted surface of the brain. Recently,
others found 'gamma band activity' in other parts of the brain, such as
the hippocampus and cerebellum. Scientists at the COBRE Center for
Translational Neuroscience at UAMS have discovered that parts of the
reticular activating system, the part of the brain that controls sleep,
dreaming and waking, exhibit 'gamma band activity'. In fact, nerve
cells in this area prefer to fire at ~40 Hertz when stimulated. This
means that the reticular activating system activates the rest of the
brain when we are alerted, and it does so, not by triggering such
activity in other regions, but by itself inducing 'gamma band
activity'. This process thus recruits waking or dreaming. This novel
mechanism may allow the development of new stimulants and anesthetics
that can modulate this brain rhythm.
Advance. We discovered that parts of the reticular activating
system, the part of the brain that controls sleep, dreaming and waking,
exhibit 'gamma band activity'. In fact, nerve cells in this area prefer
to fire at ~40 Hertz when stimulated. This means that the reticular
activating system activates the rest of the brain when we are alerted,
and it does so, not by triggering such activity in other regions, but by
itself inducing 'gamma band activity'.
Grant Support. Supported by Core Facilities of the
COBRE P20 RR20146, and individual grant support R01 NS20246.
Public Health Impact/Significance. This novel mechanism may
allow the development of new stimulants and anesthetics that can
modulate this brain rhythm.
Link to article.
http://www.ncbi.nlm.nih.gov/pubmed/20463196
Gamma band unit
activity and population responses in the pedunculopontine nucleus.
Simon C, Kezunovic N, Ye M, Hyde J, Hayar A, Williams DK, Garcia-Rill E.
J Neurophysiol. 2010 Jul;104(1):463-74. Epub 2010 May 12. PMID: 20463196
[PubMed - in process]
Institution and State. University of Arkansas for Medical Sciences,
Arkansas COBRE Center for Translational Neuroscience.
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