This is a guest post by Autism Speaks staffer Jane Pickett, Ph.D.
The 10th annual international gathering of autism scientists, researchers and advocates, known as IMFAR, (International Meeting for Autism Research), was held last month. At the meeting, the prestigious Slifka/Ritvo award for research innovation went to a project using post mortem brain tissue to help researchers using MRI on living subjects to define boundaries between various brain regions. This research is important because every brain is a little bit different and we need new tools to accurately compare brain areas across individuals.
Drs. Thomas Avino and Jeffrey Hutsler at the University of Reno tackled the problem of defining the border between brain cells making up the ‘gray matter’ and the ‘white matter’ located in the center of the brain) by examining brain tissue of donors to the Autism Tissue Program. Their project, ‘Quantification of the gray/white matter boundary in Autism Spectrum Disorders’, assessed 3 brain regions in 8 males with autism and 8 age- and sex-matched control donors.
The images at the left mark the location of neurons in the lower cellular layer of the cortex, Layer VI, and also the white matter below it. The image (left) of an unaffected donor shows a typical transition zone; the autism brain specimens have a poorly defined zone, with the cell bodies of neurons spilling into areas where they are not expected to be. Looking directly at brain cells, it is easy to understand the MRI reports of ‘poor distinctiveness’ between cortical gray and white matter and now imaging researchers have a mathematical model to consider in their assessments of gray/white matter as they study brain development in children with autism.
Independent examination of other autism brain samples by post doctoral student Adrian Oblak from Boston University School of Medicine also showed many neurons atypically located in white matter. More specifically, these neurons were found in the cortex involved in emotion and memory process and face processing. Microscopic images of marked cells in this area, the posterior cingulate gyrus, show cells on the right, in the autism brain, massing into the white matter.
Why is this important in today’s autism world? Years of study of the developing human brain show that at embryonic brain cells begin to ‘climb’ up to the cortical surface and by 5 months gestation virtually all are located above the new myelin-dense ‘white matter’. A delay in this migration during the second trimester of pregnancy is thought to be caused by a lack of proper cell signaling due to a genetic and/or environmental impact on the developing brain. What is important is that this change in brain structure is seen into adulthood in brains of donors with autism; therefore, further research of brain cell architecture, combined with brain tissue genotyping, will reveal more about changes occurring during the development of the central nervous system. The correct configuration of the cortical cell layers is crucial for further maturation and functionality of the brain. A number of coordinated events need to occur for this early development such as proper signals for cell birth, migration, maturation and final proper distribution of new brain cells. Genes that guide these events are becoming better understood (read about a new genetics study).
What does this have to do with you? None of this research is possible without brain donation. If you are interested in learning more about the Autism Tissue Program, or registering you and your family with the program, please visit our website at www.autismtisssueprogram.org, email us at email@example.com or call 1-877-333-0999.