Musing on Myelin --
I read recently about a study that links myelin and schizophrenia. (<hhttp://www.sciam.com/article.cfm?articleid=24727C44-E7F2-99DF-3A95DD386F68E61C&chanId=sa017) I don't begin to pretend I understand this but what I got from it was this: a type of glial cell, oligodendrocytes, support axons and produce the myelin that insulates the axons central nervous system neurons. If too many oligodendrocytes are produced, they don't split and branch as frequently and thus produce thinner myelin.
The mice subjected to the experiment showed a "18 percent slower speed for information transmission in the brains" and less curiosity or at least less response to things - intruders, desire to explore. They were "more sensitive of amphetamines" which is a "hallmark of schizophrenia". The researchers also found that the number of some dopamine receptors had increase.
It is suspected that Alzheimer's is caused in part by the destruction of myelin by plaque. And, oligodendrocytes have been associated with other types of mental illness - bipolar, OCD, depression as well as multiple sclerosis. In fact I have a friend who is bipolar. She had a sister with MS and a brother with schizophrenia and long suspected on her own that somehow these illness were connected.
Add to this mix a report in today's New York Times proudly proclaims "Chemotherapy Fog Is No Longer Ignored as Illusion" which reports that people who have chemotherapy often have cognitive difficulties of the type I and/or others with a TBI experience: short term memory loss, trouble concentrating, retrieving words, and multitasking, and generally feeling they are not as mentally sharp as they once were. (The fact these facts were so often disbelieved, dismissed, and generally ignored is also very much like the response to MTBI). These symptoms are also present in the beginning stages of Alzheimer's.
I try to get my brain around this as I remember the experiences I had first, with the initial aftermath of my head injury and then with my experience on all those psychiatric drugs. I know that the chemical make-up of my body changed when I hit my head. The extensive gum disease, and subsequent periodontal surgery I had, was caused by a change in the chemical makeup of my saliva. This change the dentist told me was probably caused by the stress of the head injury. (I know it wasn't poor dental hygiene because before the HI I had very little plaque no matter how infrequently I flossed or went to the dentist - This is true now also.)
So, did the HI cause other chemical shake-ups in my body? Is it possible that oligodendrocytes, or more generally myelin, were affected, or those chemical or receptors that govern myelin? How does oligodendrocyte and/or myelin relate to dopamine and does it all relate to serotonin? Do the toxins in chemotherapy also weaken or kill off myelin? I think there is a connection here - I don't know even to define it. I wonder if anyone is looking at all this or if the researchers, like so many others, are comfortable in their limited field of expertise.
I wonder how many doctors outside the fields of neuroscience, neurology, and psychiatry know about the cognitive problems that can come from drugs. And if they do, how many care. As one person quoted in the New York article said, the doctors think their only responsibility is to treat whatever ailment you came in for. Perhaps continued study of myelin will force doctors to broaden their view.
The mice subjected to the experiment showed a "18 percent slower speed for information transmission in the brains" and less curiosity or at least less response to things - intruders, desire to explore. They were "more sensitive of amphetamines" which is a "hallmark of schizophrenia". The researchers also found that the number of some dopamine receptors had increase.
It is suspected that Alzheimer's is caused in part by the destruction of myelin by plaque. And, oligodendrocytes have been associated with other types of mental illness - bipolar, OCD, depression as well as multiple sclerosis. In fact I have a friend who is bipolar. She had a sister with MS and a brother with schizophrenia and long suspected on her own that somehow these illness were connected.
Add to this mix a report in today's New York Times proudly proclaims "Chemotherapy Fog Is No Longer Ignored as Illusion" which reports that people who have chemotherapy often have cognitive difficulties of the type I and/or others with a TBI experience: short term memory loss, trouble concentrating, retrieving words, and multitasking, and generally feeling they are not as mentally sharp as they once were. (The fact these facts were so often disbelieved, dismissed, and generally ignored is also very much like the response to MTBI). These symptoms are also present in the beginning stages of Alzheimer's.
I try to get my brain around this as I remember the experiences I had first, with the initial aftermath of my head injury and then with my experience on all those psychiatric drugs. I know that the chemical make-up of my body changed when I hit my head. The extensive gum disease, and subsequent periodontal surgery I had, was caused by a change in the chemical makeup of my saliva. This change the dentist told me was probably caused by the stress of the head injury. (I know it wasn't poor dental hygiene because before the HI I had very little plaque no matter how infrequently I flossed or went to the dentist - This is true now also.)
So, did the HI cause other chemical shake-ups in my body? Is it possible that oligodendrocytes, or more generally myelin, were affected, or those chemical or receptors that govern myelin? How does oligodendrocyte and/or myelin relate to dopamine and does it all relate to serotonin? Do the toxins in chemotherapy also weaken or kill off myelin? I think there is a connection here - I don't know even to define it. I wonder if anyone is looking at all this or if the researchers, like so many others, are comfortable in their limited field of expertise.
I wonder how many doctors outside the fields of neuroscience, neurology, and psychiatry know about the cognitive problems that can come from drugs. And if they do, how many care. As one person quoted in the New York article said, the doctors think their only responsibility is to treat whatever ailment you came in for. Perhaps continued study of myelin will force doctors to broaden their view.