Monday, November 13, 2017

Brain's Glial Cells Spark Seizures

Fidel Empalmado

I chose to research an article about seizures. My wife has epilepsy, and has suffered from seizures for several years now. She is on the highest dose of medication that she can be on; however, she still has seizures if she has added stress, lack of sleep, or poor diet (which happens too often with three children at home).  On top of having epilepsy, she is also prescribed medications for her depression and anxiety. This condition not only affects her physically and emotionally, but also takes a toll on the whole family. I have a great interest in educating myself more on this topic hoping to eradicate her seizures or lessen the frequency of them.

In our class, I have learned that electrical signal or activity in the neurons are caused by ions flowing in and out of the protein channels in the plasma membrane of cells.  Ions are atoms or molecules with a net electric charge due to the loss or gain of one or more electrons. The ions that are involve in propagating electrical signals are NA+(Sodium), Cl-(Chloride), Ca2(Calcium), K+(Potassium) and A- (negatively charge anions).

In this article the author discovered a possible underlying link in cause of seizures. Overexcited neurons have always been the known cause for seizures, but this research shows just what “sparks the cells to go haywire”.

While studying fruit flies, scientists found that “when glial cells in the cortex of fruit flies cannot properly control their calcium levels, they leave neighboring neurons vulnerable to seizures.
Researchers at the Massachusetts Institute of Technology identified a genetic mutation that causes fruit flies to seize when they are exposed to heat or vibration. On studying the mutation, they found that it affects a gene called zydeco that controls calcium exchange inside glial cells.”
Additionally, this mutation that affects zydeco gene on fruit flies, prevents tiny calcium fluctuations from occurring in glia, which Melom believes results in a buildup of calcium inside the cells.

Because stress such as heat usually boost calcium levels, the combination could trigger “some sort of glial reaction that spirals into a seizure”. Another major question is how glial cells communicate with the neurons, prodding them to over excite. The researchers believe that because the same version of zydeco gene exist in mammals, the answer could help explain the genesis of epileptic seizures in humans as well.

More simply put, overexcited neurons cause the seizure, but there are several ways that neurons get overexcited. Researcher Jan Melom found that “the mutation identified in the study prevents tiny calcium fluctuations from occurring in glia, which Melom believes results in a buildup of calcium inside the cells”. This causes a depolarized intracellular environment making neurons overexcited. It is very interesting to hear this theory because my wife did not have seizures until 5 years ago. With her current lifestyle as a mother and having a husband going to school full time, she has become much more prone to have seizures under this stressful environment. I am anxious for more updates about this scientific breakthrough with the hopes of finding a cure to this condition.

Scientific American
Melinda Wenner Moyer
https://www.scientificamerican.com/article/brains-gilal-cells-spark-seizures/





No comments:

Post a Comment