Advances in Autism Research at the Society for Neuroscience Meeting

During an unusually sunny autumn week in November, 35,000 neuroscientists gathered in Washington, D.C., for the 35th annual Society for Neuroscience meeting to discuss the most recent advances in their quest to understand the brain. With nearly 17,000 scheduled presentations, numerous parallel speaker sessions and more than 1,000 vendors and organizations vying for the attention of visiting scientists, it was easily the largest science fair in the world. It can be a daunting task to make your selection of presentations, or finding just that one scientist you have been waiting to meet all year.

Fortunately, autism got a major share of the attention this year, as it was the subject of the annual Neurobiology of Disease workshop, one of the featured presentations of the weeklong meeting. For 25 years the Society for Neuroscience conference has been kicked off by this daylong workshop highlighting a single disease, and on Friday, Nov. 11, the Neurobiology of Disease workshop was solely dedicated to autism.

"We've been waiting for this for 10 years," commented Cure Autism Now (CAN) board member David Baskin, M.D. The workshop was sold out, and from 8 a.m. to 5 p.m., all eyes were on autism as scientists from different fields came together under the subject heading, "Developmental Neurobiology of Autism Spectrum Disorders: Clinical Phenotypes, Neurobiologic Abnormalities & Animal Models." Students and researchers spent the day hearing lectures from autism experts and then participating in small breakout discussion sessions targeting different features of autism.

"The selection of autism as the subject of this prestigious workshop signifies that autism has finally reached mainstream interest in the scientific community," explained Cure Autism Now Science Director Sophia Colamarino, Ph.D. "The importance of this cannot be underestimated."

During the course of the conference, another 108 presentations were made about autism or Asperger's Syndrome (increased from 72 last year), a good number of them by CAN-funded researchers. Two entire sessions were specifically dedicated to autism, discussing subjects such as animal models of autism and imaging the autistic brain.

Research using the Autism Genetic Resource Exchange (AGRE), established in 1997 by CAN, triggered the establishment of several animal models, mimicking phenotypes of autism by using mice with genetic deficiencies in genes such as "Engrailed-2" or "Reelin". One intriguing aspect of mice with lowered amounts of Reelin protein is that males have fewer Purkinje neurons in their cerebellum, similar to humans with autism. Female mice with the same deficiency are completely normal. A study by Giovanni Assenza, Ph.D., and colleagues now suggests that the protective effect in females is caused by higher levels of estrogen during early development of the brain. While the study is still preliminary, it could lead to a better understanding of why autism is more prevalent in boys and men.

In a CAN-funded study that received international attention in journals such as Nature and New Scientist, Eric Peterson, Ph.D., and colleagues reported that the brains of parents of individuals with autism are different from the brains of parents of typically developing children. Although the parents of autistic children did not share the disease with their children, they did share some anatomical brain similarities. When they compared brain scans of 40 parents of autistic children with those of a control group they saw a reduction of size in somatosensory cortex, important for understanding social information such as facial expressions, and the cerebellum, which plays a role in coordinating movement. On the other hand, areas linked to movement planning and imitation, the motor cortex and basal ganglia, were unexpectedly increased in autistic children and their parents. While it is not yet possible on a large scale, the time may come when scanning for such differences in the brain could help identifying families with the risk of autism. Along these lines, Cure Autism Now has organized a neuroimaging meeting in January 2006 to call together researchers from across the country to discuss the next steps for using imaging technologies to rapidly aid the understanding and diagnosis of autism.

This year's Presidential Symposium also had relevance to autism. In an exciting update of her work on diagnosis and treatment of learning disorders, Paula A. Tallal, Ph.D., showed evidence that predisposition for language impairments could be diagnosed as early as six months of age. By testing for "rapid auditory processing" in infants, which ultimately become important for learning distinctions between related syllables, she predicted future language impairments with an accuracy of 91.6%. Together with Michael Merzenich, Ph.D., Dr. Tallal pioneered the software FastForWord, which retrains the brain incrementally through games and simple exercises. Dr. Tallal announced that FastForWord has just been introduced into 235 schools in Philadelphia to assist students with learning disabilities such as dyslexia. Following upon the success of their FastForWord work, CAN awarded a genius grant to Dr. Merzenich in 2004 to begin development of similar neural-retraining strategies for autism.

In sum, the 2005 Society for Neuroscience meeting was a milestone for autism research. At the conclusion of the meeting Tom Insel, M.D., director of the National Institute of Mental Health, expressed his excitement at the increase in autism research being presented: "Five years ago there was a trickle with a few posters. This year it is more of a river: The Neurobiology of Disease workshop and over 100 abstracts, with special poster sessions just for autism. This is incredible progress."