Society for Neuroscience--37th Annual Meeting.

New research has found that some of the brain abnormalities and behaviors associated with autism also are present in the parents and siblings of individuals with the disorder. Rare mutations on a specific gene appear to be risk factors for autism. Scientists have also discovered that avoidance of eye contact with other people is not, as previously believed, a primary cause of the social impairments observed in autism. All of these studies promise to shed light on more effective methods of diagnosis and treatment. Autism affects as many as 24,000 children born in the U.S. each year. It is a brain disorder that impairs a person’s ability to think, feel, communicate, and relate appropriately to the outside world. These behaviors can range from mild to severely disabling, but their impact on the lives of individuals with the disorder and on their families is almost always devastating. People with autism often have other debilitating brain disorders, including attentiondeficit/hyperactivity disorder, obsessive–compulsive disorder (OCD), epilepsy, and depression. Although the exact cause of autism is unknown, experts believe that it is associated with abnormal brain developments that emerge in part as a result of genetic factors. A better understanding of what exactly goes wrong in the developing brains of autistic children might be able to help scientists identify the genes involved with autism and thus to generate better methods of diagnosing and treating the disorder. Many areas of the brain have been implicated as an etiologic factor, but pinpointing specific brain structures has proved challenging. Brain development and cognitive maturation are difficult to control in clinical studies of autistic children. Researchers at the University of Colorado, Colorado State University, and the University of Denver decided to study the brains of parents of autistic children to see whether they also had abnormalities associated with the disorder. If they did, those abnormalities might be the heritable ones involved in the emergence of autism. For the study, 40 parents of autistic children and 40 agematched and sex-matched controls received magnetic resonance imaging (MRI) brain scans. Scientists identified many brain regions in which “the autism parent group was either smaller or larger than in the brains of the adults with a negative family history,” reports Eric Peterson, PhD. These areas include the cerebellum, which plays a role in cognitive thinking (speech, learning, emotions, and attention) and in motor function, and the basal ganglia, a brain region associated with compulsive and ritualistic behavior. People with autism often have difficulty with changes in their routines and can develop patterns of repetitive behaviors. These findings offer hints as to which brain abnormalities might be heritable with autism. One of the next steps, says Dr. Peterson, is to confirm the findings in studies on pairs of twins when only one twin has autism and to use functional brain imaging for family members to see whether the malfunctioning of those same brain regions is also heritable. At the University of Wisconsin-Madison (UW), researchers found that the non-autistic brothers of people with autism show the same avoidance of eye contact as their autistic siblings when they viewed images of strangers and family members. Abnormal eye contact is common in people with autism, and it is often one of the behaviors first noticed in children with the disorder. The non-autistic brothers, like their autistic siblings, had smaller-than-normal amygdalas, an area of the brain involved in understanding emotional facial expressions and in feeling fear in social situations. Using computerized technology, the UW researchers measured the amount of time that three groups of participants, 6 to 18 years of age, spent looking at the eyes of people in pictures. The groups included nine boys with autism, nine non-autistic brothers of individuals with autism, and nine boys with typical development. Intelligence quotient (IQ) scores were similar for the non-autistic brothers (average, 120) and the control group (average, 119) but were lower for the autistic group (95). Nevertheless, the autistic subjects and the non-autistic brothers were most similar when it came to eye contact: both groups showed decreased eye contact in relation to the control group. The low incidence of eye contact occurred even when the Society for Neuroscience, 35th Annual Meeting