"New Theories Help Explain Mysteries of Autism"
A recent article in the Science Times section of The New York Times (December 28, 1999, p D1 and D4) by Sandra Blakeslee ("New Theories Help Explain Mysteries of Autism") is a survey of current thinking about a number of important questions regarding autism. Salient questions include "when" and "where" in the brain critical neurodevelopmental processes go awry. The reporter quotes Dr. David Amaral of the University of California at Davis: "...an entire brain circuit has been compromised... " Another important question: Is the incidence of autism increasing? Although there is a widespread impression that there has been an increase in the incidence of autism (current estimates range between 1:500 and 1:1000), Dr. Marie Bristol Power of the National Institute of Child Health and Development cautions that the data are not yet clear that there is a higher incidence or that the availability of better diagnosis are responsible for this impression. The author quotes Dr. Bennett Leventhal of the University of Chicago: ":at least five or six genes contribute to autism," citing recent data pointing to chromosomes 7, 13, and 15. Although the precise role of putative genes is not clear, they may be responsible for nerve growth and migration factors during critical stages of nerve cell development during fetal development or the first few years of life. The concensus remains that aberrant neurodevelopment probably occurs during the first or second trimester of pregancy, although Dr. Eric Courchesne believe it is equally likely that the aberrant event occurs postnatally. Dr. Amaral believes that key brain regions, such as the amygdala (recognition of facial expressions; gaze direction) or cerebellum (shifting attention) are involved. He also refers to experiments in monkeys pointing to brain cells specialized to respond to "moving hands and faces but not other moving things. " Copying the behavior of other monkeys is attributed to nerve cells called "mirror neurons. "
This article is the most recent of several autism-related articles that appeared in The New York Times during 1999. They can be viewed at no charge on the NYT Web site. However, it is necessary to register on-line before access is granted. An alternative is to look up the articles in a public library.
The complete article is at: New Theories Help Explain Mysteries of Autism
Other pertinent articles published in the NYT Science Times section during 1999 are:
January 26, 1999, Child's Movements May Offer an Early Clue to Autism, by Sandra Blakeslee
April 6, 1999, A Syndrome With a Mix of Skills and Deficits," by John O'Neil (re Asperger syndrome)
December 9, 1999, A Drug Used for Autism Is Under Fire in New Study, by Sandra Blakeslee (re secretin)