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Brain Development Initiative



Introduction
The mysteries surrounding the brain are tremendous. Modern science still knows very little about the body’s most complex organ. The Brain Development Initiative hopes to solve the mysteries concerning the brain’s role in the development of autistic spectrum disorder (ASD). The Brain Development Initiative was originally spearheaded by the Cure Autism Now (CAN) Foundation1, which merged with Autism Speaks in early 2007.2 The Brain Development Initiative hopes to expand on previous research related to which factors cause abnormalities in children with developmental disabilities. Two promising areas of groundbreaking research are examining the presence of white matter in the brain and abnormal brain growth in children with autism spectrum disorders.1


White Matter
White matter is “the commonly used term for the myelinated axons that provide connections between neurons, or grey matter.”3 As the interest of certain diseases like dementia and Alzheimer’s grew, so did science’s curiosity in the role white matter plays in brain function. The aim of the Brain Development Initiative is “to bring together many methods and scientists to capitalize on the findings of regional abnormalities in the development of white matter in the autistic brain.”1 The Brain Development Initiative is led by Dr. Martha Herbert of Massachusetts General Hospital. Dr. Herbert was a co-author of the 2003 study Larger Brain and White Matter Volumes in Children with Developmental Language Disorder.4 The objectives of Dr. Herbert’s research “include studying what makes some autistic brains unusually large, how the parts of the brain are connected and coordinated with each other, and how we can develop measure sensitive to changes in brain function that could result from treatment interventions.”5 Past studies have demonstrated that individuals with autism tend to have larger brains, but the Brain Development Initiative seeks out answers as to why this abnormality exists.


There are numerous questions being posed relating to brain growth and autism. Some of these vital questions ask: Is brain overgrowth the reason for poor development? Or is the overgrowth in response to some other, less obvious problem? Why is the white matter area of the brain most affected by overgrowth? What part or parts of the brain are abnormal?1 By answering these questions the BDI can take pivotal steps towards understanding what causes autism spectrum disorder.



Abnormal Brain Growth in Children with ASD
A 2003 study, entitled Evidence of Brain Overgrowth in the First Year of Life in Autism, measured the head circumference of 48 children with ASD aged 2 to 5. The study concluded that the “clinical onset of autism appears to be preceded by 2 phases of brain growth abnormality: a reduced head size at birth and a sudden excessive increase in head size between 1 to 2 month and 6 to 14 months. Abnormally accelerated rate of growth may serve as an early warning signal for autism.”6 The abnormal growth of the brain is temporary. After the first few years of development the “growth of some brain regions affected by autism appears to slow considerably.”7 The results of this and similar studies have laid the foundation for future studies designed to explain why this abnormal brain growth occurs. Eric Courchesne, Ph.D., a co-author of the 2003 study, has recently conducted two more studies designed to determine which factors cause the abnormal brain growth.



A 2011 study conducted by Dr. Courchesne aimed to determine if early brain overgrowth is connected to excess neuron numbers in the prefrontal cortex (PFC).8 The study concluded that children born with autism spectrum disorder and abnormal brain growth had “an excess number of brain cells, or neurons, in the part of the brain known as the frontal cortex.”7 A 2012 study by Dr. Courchesne sought to address why the excess amount of neurons occurs in children with ASD who experience abnormal brain growth. The study determined there is dysfunction in several gene networks that possibly affect the number of neurons that are generated during the second trimester of pregnancy.7 During the second trimester about 40 billion neurons are produced in a normally developing prenatal brain. However, not all of these neurons are meant to survive. In a normal developing brain neurons undergo apoptosis, which is a genetically regulated form of cell death.9



The 2012 study also found abnormality in “gene networks that affect the number of neurons that survive through the second and third trimesters….This may contribute to the excess of neurons and abnormal brain wiring.”7 This important conclusion leads researchers to believe that the onset of autism occurs in the womb, ruling out many speculations about post-natal causes of autism (vaccines, diet, postnatal chemical exposure, etc.) With these findings Dr. Courchesne concludes that “eventually it will be possible to develop ways to foster both growth of more appropriate cells and connections and a pruning away of unwanted excess. And [he] believe[s] this may become possible at any age, not just early childhood.”7 His hope, and the hope of many autism advocates all over the world, is that better understanding of the development of autism can lead to the development of both medical interventions and improvements in our existing behavioral interventions.




Conclusion
Although science may be years, if not decades, away from fully understanding the role the brain plays in autism, enterprises like the Brain Development Initiative are helping science chip away at the mysteries of the brain bit by bit. Continued research by accomplished neurologists, such as Dr. Herbert and Dr. Courchesne, will help further our understanding of a disorder that has an ever-increasing rate of incidence. The solution to autism spectrum disorder will not come from just one approach or focus, but is dependent on incorporating outcomes at various levels of research. The studies mentioned in this article are but a fraction of those being conducted that concern autism spectrum disorders.



References