For the press conference, a small group of researchers were singled out and gave advance summaries of their work. David Amaral of U.C. Davis is the president of INSAR (the International Society for Autism Research ) and hosted the press conference.
Amaral gave an introduction. This is the 10th IMFAR, and they returned to San Diego, where the first conference was held. The fist conference had 250 attendees. This one will have about 2,000. He stressed the focus on research into causes and treatment, the wide range of studies including environmental causation, and the strong passion and excitement of the researchers.
They found a number of interesting results. They looked at specific bundles of of nerves involved in long-range connectivity within the brain. Connectivity between the temperal lobe and limbic system (e.g. amygdala) are different amongst autistics from very early on. They looked at a measure called “fractional anisotropy”, or FA. For young autistics, FA is high. FA grows with time (it is a measure of maturity), but it grows slower than for non ASD kids. Result—FA is high for young (<30 month old) children, but low for older autistics. This is consistent with earlier work showing lower maturity (FA) for older autistics.
During questions, there was much dicussion of other aspects of Dr. Courchesne’s research. There is a 2x increase in brain cells in the frontal cortex in very young autistics. This points to causation, at least for a large group, in very early events. There is also evidence from post mortem studies giving genetic evidence of dysregulation of functions that regularte cell number, cell migration, patternng of the brain, left/right brain symmetry and other factors of the brain. Not only are there differences in genetic expression and genetic pathways, but they are age dependent.
This brings up an important point for future research efforts. Researchers need to be aware that so many factors could be age dependent. Also, this gives some insight into possible developmental trajectories that the brain may undergoe. It was posited that the
The idea that FA starts out higher is new and presents a possible mechanism for different brain development in autistics. It was posited that the early structure of the autistic brain could result in the different developmental path.
On a related topic in the questions, I believe it was from David Amaral, it was noted that “precocious” brain growth is associated with regression. While it is known that large head diameters are common amongst autistics, changes in brain growth are observable as early in 4-6 months of age, well before the regression occurs.
And that’s just the first person in the panel! I will get to the rest of the press conference shortly.
passionlessDrone: Hi Sullivan -Nice opening post.This brings up an important point for future research efforts. Researchers need to be aware that so many factors could be age dependent. Nice! [Also you have a sentence that dies out up there.]On a related topic in the questions, I believe it was from David Amaral, it was noted that “precocious” brain growth is associated with regression. While it is known that large head diameters are common amongst autistics, changes in brain growth are observable as early in 4-6 months of age, well before the regression occurs.Very interesting finding. Luke measured 95% percentile in head growth ~ 6 months. We were like, 'he's gonna be smart'. Hah.- pD
Anne: I'd also like to see some research on how these differences in brain development could account for some of the aptitudes commonly found in autistics.
Almost all studies show that at birth, a boy's brain is bigger than a girl's brain. At birth, the average brain of boys is between 12-20% larger than that of girls. The head circumference of boys is also larger (2%) than that of girls.
http://faculty.washington.edu/chudler/heshe.htmlIf boys head size is only 2% bigger then girls, but brain size is 12-20% bigger, I wonder if this makes boys more susceptible to problems if there is additional ASD related rapid brain growth without proportional head growth.