Mice with multiple sclerosis-like condition walk again after human stem cell treatment

Link
http://www.sciencedaily.com/releases/2014/05/140515123204.htm
This article was written by the University of Utah Health Sciences and published on May 15, 2014.

Summary
In one experiment, researchers transplanted human neural stem cells into severely disabled mice with conditions similar to multiple sclerosis. They had predicted this wasn't going to be beneficial to the mice at all because the stem cells would be rejected- in other words, destroyed. However, to their astonishment, the rodents regained their motor skills within 10-14 days after the transplant, and haven't slowed down for the six months following the experiment. It also turns out that the researchers' prediction was true- the stem cells disappeared in the mice a week after the transplant. However, there was enough time before the rejection for the stem cells to send chemical signals instructing the mice's own cells to repair damaged myelin sheath. This explained the rodents' quick recovery and opens up a new field of research in treating humans with multiple sclerosis. Because transplanting stem cells into humans is challenging, alternate ideas are arising. For example, one idea is to put the chemical signals into a drug for patients with multiple sclerosis. The researchers are shooting for clinical trials and plan to assess its safety using mice.  

Relevance
This article relates to when we learned about the nervous system, particularly the disease, multiple sclerosis. We learned that people with this condition have damaged myelin sheath. Electrical signals which communicate information to other neurons or effector cells take a longer time to travel down the axon. Normally, a functioning myelin sheath speeds the transmission of the signals by cutting some distance- signals jump from node to node. However, the absence of functioning myelin sheath means there's more distance for signals to cover, meaning that it takes up more time for them to get to other neurons or effector cells. This slows communication within the nervous system, causing motor skills such as walking to be impaired. As discussed in the article, repairing the damaged myelin sheath mean the speed of the transmission of signals would return to normal, and motor skills would be regained. This article also relates to the immune system, which is something we'll be learning about soon.