estrogen fluctuation affects epileptic seizures
epilepsy is an abnormal wave pattern invading normal brain tissue from abnormal
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HOW BIOFILM COULD CAUSE SEIZURES
neurons have excitatory synapses and inhibitory synapses
if you regard epilepsy as an unfavourable modulation of these then it
follows that biofilm toxins are well able to modulate dna expression
and other factors to promote an excess of excitatory synapses and a
deficency of inhibitory synapses
its a simple model and seems to be a good explanation and also that
you would have a heap of compounding factors summing to give the total effect
this would include mercury and other heavy metals and organic toxins
you can also see how the ketogenic diet works, its very brutal and
stymies synapse function by depriving the brain of glucose, but keeps
the brain alive by fueling through the ketone metabolism pathways
leaky gut is strongly implicated in lks and seizures imo
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ESTROGEN FLUCTUATION AFFECTS EPILEPTIC SEIZURES
In more than a third of women with epilepsy, seizures fluctuate
across the menstrual cycle, due in part to continually fluctuating
effects of estrogen on the neural circuitry in the hippocampus, a
region of the brain involved in learning and memory - and in
epileptic seizures.
Northwestern University scientist Dr. Catherine S. Woolley, a pioneer
in understanding the effects of hormones on the structure and
function of neural circuitry, says understanding how estrogen
contributes to seizure activity could lead to novel and needed
therapeutic targets for anti-epileptic drugs.
On April 30, Dr. Woolley told fellow scientists meeting at
Experimental Biology 2007 in Washington, DC, that new and unexpected
findings in her laboratory suggest where such therapies might
intervene. Dr. Woolley had been selected to present this year's C. J.
Herrick Award Lecture, a distinguished award presented as part of the
scientific program of the American Association of Anatomists.
A decade ago, Dr. Woolley discovered that estrogen increases the
number of excitatory synapses on neurons in the hippocampus.
Excitatory synapses activate neurons, sending and receiving
neurotransmitters, explaining how estrogen could enhance learning and
memory consolidation. Beyond the fact that estrogen played this role,
her findings surprised the scientific community for two more reasons.
First, based on natural hormone cycles, the synaptic turnover was
very rapid, demonstrating remarkable plasticity of the brain. Second,
the estrogen-influenced changes were taking place in the hippocampus,
outside what were then considered the traditional hormone-sensitive
regions of the brain.
Dr. Woolley's research since has focused on these estrogen
fluctuations and how they drive synaptic changes. She now has shown
that, in addition to their effect on excitatory synapses that turn on
neurons, fluctuating levels of estrogen also have an equally dramatic
effect on the inhibitory synapses that silence neurons. Using a
combination of electrophysiology to measure synaptic function and
nanoscale measurements of synaptic structure, her team has shown that
estrogen suppresses the release of inhibitory neurotransmitters, and
that this occurs by regulating vesicles at inhibitory synapses
(vesicles being the membranes that contain neurotransmitters).
And once again, there was an additional, surprising finding, says Dr.
Woolley. Estrogen receptors are typically found in the cell nucleus
where they regulate the expression of genes, a relatively slow
mechanism to change brain function. Her group found that these
receptors also are located on vesicles at inhibitory synapses and
that estrogen mobilizes these vesicles toward synapses. The synaptic
location of estrogen receptors shows that the effects of this hormone
in the brain can be targeted to individual synapses, fine-tuning how
neurons communicate, and on a much more rapid time scale then
previously appreciated. The estrogen regulation of neurotransmitter
vesicles points to novel targets for anti-epilepsy therapies.
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EPILEPSY IS AN ABNORMAL WAVE PATTERN INVADING NORMAL
BRAIN TISSUE FROM ABNORMAL
Washington, D.C. -- Neuroscientists have long believed that vision is processed in the brain along circuits made up of neurons, similar to the way telephone signals are transferred through separate wires from one station to another. But scientists at Georgetown University Medical Center discovered that visual information is also processed in a different way, like propagating waves oscillating back and forth among brain areas. Their findings are published in the July 5 issue of the journal Neuron.
“What we found is that signals pass through brain areas like progressive waves, back and forth, a little bit like what fans do at baseball games,” said the study’s corresponding author, Jian-young Wu, Ph.D., an associate professor in the Department of Physiology and Biophysics at Georgetown. Just as the stadium wave is coordinated and travels through the crowd, a collective pattern emerges from the activities of millions of neurons in the visual areas, he said, explaining, “It simply makes sense that brain function is the result of large numbers of neurons working together.”
This challenges longstanding notions about how the brain processes sensory information, Wu said. “One traditional model theorizes that neurons are hooked together into specific circuits. However, new imaging methods tell us that there are more than just circuits.”
Wu and his colleagues visualized wave-like patterns in the brain cortex using a new method called voltage sensitive dye imaging. They used a special dye that binds to the membrane of neurons and changes color when electrical potential passes along active neurons.
Traditionally, scientists have studied brain activity by placing electrodes in the brain and measuring the electrical currents that are related to neuronal activity. Because it is difficult to put many electrodes into the brain, the spatiotemporal pattern of the neuronal activity has long been ignored. “Now, with optical methods, we can watch sequential activation of different sectors of the visual cortex when the brain is processing sensory information," Wu said.
Wu believes wave patterns play an important role in initiating and organizing brain activity involving millions to billions of neurons. A few years ago, Wu's imaging group uncovered spiraling waves resembling little hurricanes in animal epilepsy models. Wu thinks that through this hurricane-like spiral pattern, a small area of damaged neural tissue can generate a powerful storm that invades large normal brain areas and starts a seizure attack. This hypothesis would mean that disorders such as epilepsy could be viewed not just as mis-wiring in the brain, but as an abnormal wave pattern that invades normal tissue.
Finding waves during visual processing is an important step toward understanding how the brain processes sensory information, explained Wu. This understanding has the potential to help scientists understand the abnormal waves that are generated in the brains of patients with Parkinson's disease and epilepsy, and how the mind fails when the brain of an Alzheimer’s disease patient cannot properly organize population neuronal activity, he said.
http://explore.georgetown.edu/news/?ID=26050