today we're going to consider a deagain rattive disease, multiple ser sclero that has a very different cause. it is an autoimmune disease. so the immune system developed in order to protect us against foreign invaders like viruses and bacteria. and an occasion it errs and recognizes a protein in the body and becomes the target of an immune attack. it's been obvious to many people all along that the variety of organs in the body that are susceptible to this kind of attack. for example, we've known that type 1 diabetes is an autoimmune disease that hits cells in the pancreas, that release insulin or crohn's disease is an autoimmune disease that affects the bowel it has been less obvious although it's perfectly clear that autoimmune diseases also affect the brain even though the brain has this protective barrier called the blood-brain barrier, autoimmune disease can penetrate that and attack it. and this is where we see a multiple sclerosis. what causes this immune attack and multiple sclerosis is not completely clear. there are a number of environmental and genetic factors that are known

in our 10th episode we consider a amyotrophic teral scleros and spinal muscular atrophy. >> we're going to have today amyotrophic lateral sclerosis and spinal muscular atrophy, two diseases that affect motor neurons. and this is a continuation of a theme we've had for the last several programs. we will consider disorders that affect the motor system. now if you are going to affect any cell type, and really have an impact it's hard to think of one that is more critical for our behavior than the motor neuron. this is the output element of the nervous system. this is responsible for all of our actions. >> rose: episode 10 of the charlie rose brain series 2 underwritten by the siemens foundation, coming up. >> the charlryios brain series is about the most exciting scientific journally of our time. understanding the brain. the series is made possible by a grant from the siemens foundation. their mission is to advance the fron tears of research in the basic sciences and mathematics. funding for charlie rose was provided by the following: . >> from our captioning sponsored by rose communicatio