Myelin - Drewes Flashcards
As the oligodendrocyte/schwann cell grows mutliple layers around an axon, which end is actually growing?
The inner part is the part that is growing despite being located farther from the actual cell nucleus
Function of PLP’s vs P-0?
They have the same function - hold that tortilla tight around the axon burrito. Like some delicious guacamole
PLP in CNS and P-0 in PNS
They both stick into the extracellular space and attach together like a zipper
What do MBP’s do?
Where are they found?
Found intracellularly in both PNS and CNS myeline
They glue the intracellular part of that squished cell together - sort of like the doughy area inside the tortilla itself…
I admit that was not as good of a metaphor…
What is the difference between dismyelinationa nd demyelination?
Demyelination is normal myelin with disease or toxic exposure – causes normal myelin to be lost
Ex. Multiple sclerosis, Lead, etc
Dysmyelination is never having normal myelin because of inherited mutation
Why is it that you see areas of bright white on an MRI in the case of MS?
MRI images detecitng proton density of water
When the water is squeezed out of myelin it is dark
When demyelination occurs there is more water in the areas of demyelination
SO it shows up as a white spot… Whoa, that makes sense
Why can’t kids walk right out of the womb?
Not enough myelin right away
What abnormality is behinf Charcot-Marie-Tooth?
Genetic duplication in the chromosome causing excess PMP22
This causes dysfunction of myelin synthesis in the PNS
Charcot Marie Tooth
progressive loss of muscle tissue and touch sensation across various parts of the body
Can recreate the diseases of MS and Guillan Barre by…?
Injecting froeign myelin into the CNS or PNS - where your immune system targets the foreign body and then goes after your own myelin
What is a novel treatment for MS?
How does it work?
Natalizumab
-binds to surface intergrins on t-cells or macrophages to stop CAM’s
