Lately, the new paper by Eric Courchesne and company has been receiving a fair amount of media attention. It deals with the count of neurons in a small number of postmortem autistic brains. The neuroskeptic has written a pretty decent take of it on his blog. Unfortunately, I have not been able to find the paper online anywhere where it is not behind a paywall. UCLA biomed was not open when I went there yesterday in the morning. I hope to someday read the primary source.
In brief, the research group found a far greater number of neurons in the prefrontal cortex area of the brain than in the normal control brains. There were some other abnormalities found in the autistic brains as well, but none in the nonautistic brains. This was a very small sample aged 2-16.
This finding may strengthen some of the research findings previously reported. These are the areas that contain some of the mirror neurons. Regular readers of this blog will recall, I'm interested in mirror neurons and have written about them previously. There is a good deal of research that suggests that mirror neurons may somehow be implicated in the etiology of autism. Either a paucity of MN's or problems with connections could be involved. Though this study obviously would not suggest the former, the latter could be a possible scenario as the excess number of brain cells might have difficulty making connections to various other parts of the brain that would ensure good functioning.
These neurons are only formed during the prenatal period and no new ones grow in the brain after this. This suggests that the brain abnormalities in autism only develop in the womb and not after birth. This suggests evidence against the Age of Autism folks and others who believe that vaccines or some other exposure in the environment after birth caused the autism. I'm sure they have some sort of alternative explanation though. Of course it doesn't rule out some sort of environmental insult during pregnancy.
Nearly my entire life (more than five and a half decades now) I have wondered about the etiology of my problems. One of the first suggestions, as some Gadfly readers will remember was castration anxiety in my youth during the psychoanalytic heyday. One doctor speculated that roseola that I contracted at age one and a half was responsible. But no definitive answers as I don't buy those first two. This study does make some sense in giving some explanations for my disability. One of these areas is Broca's area which is implicated in the motor mechanics of speech. Person's who develop strokes in this area lose their ability to speak. This might be why I stopped speaking at age two and a half. These also comprise the motor areas, so they could account for my handwriting and fine motor coordination problems. However, they don't account for the twiddling (self-stimulatory) behaviors. Of course, even if this were the case with me as an individual, it does not explain why I would have grown all those extra neurons while still in the womb.
It was Courchesne who more than twenty years ago, found abnormalities in parts of the cerebellar vermis in autistics on MRI scans. Shortly after that I was his research subject in a few studies he did. I wrote an article about that
I also wrote a blog posts about some of these experiences.
When I met Courchesne, I was curious as to why some persons with autism (not including myself) had intact motor systems and if they had cerebellar impairments why they would not have ataxia or other motor problems. He stated the reason was that if damage to the cerebellum occurred early enough (during fetal development) there would be no motor impairments. So, if this is true, this might mean analogies between the excess of prefrontal neurons and the lack of connections might not be analogous to aphasias that occur when people have strokes in Broca's area.
So, there is still stuff that is left unanswered and I guess I will never know the etiology of these problems and what areas in my brain don't work correctly.
If I can ever get my hands on the actual paper, perhaps I will write a follow-up blog post.
Addendum: My sister, who's a faculty member of a university and has a subscription to various journals had access to the complete paper and I read the .pdf file. Though I have read the entire paper now, I have nothing more, unfortunately to add to my commentary at this time.