Autism Parents Club

ScienceDaily (Feb. 18, 2010) ? A study of the development of autism in infants, comparing the behavior of the siblings of children diagnosed with autism to that of babies developing normally, has found that the nascent symptoms of the condition — a lack of shared eye contact, smiling and communicative babbling — are not present at 6 months, but emerge gradually and only become apparent during the latter part of the first year of life.

Researchers conducted the study over five years by painstakingly counting each instance of smiling, babbling and eye contact during examinations until the children were 3. They found that by 12 months the two groups’ development had diverged significantly. Intentional social and communicative behavior among children developing normally increased while among infants later diagnosed with autism it decreased dramatically.

The study is published online early and will appear in the March issue of the Journal of the American Academy of Child & Adolescent Psychiatry.

“This study provides an answer to when the first behavioral signs of autism become evident,” said Sally Ozonoff, the study’s lead author, a professor of psychiatry and behavioral sciences and a researcher with the UC Davis MIND Institute. “Contrary to what we used to think, the behavioral signs of autism appear later in the first year of life for most children with autism. Most babies are born looking relatively normal in terms of their social abilities but then, through a process of gradual decline in social responsiveness, the symptoms of autism begin to emerge between 6 and 12 months of age.”

Autism is a pervasive developmental disorder of deficits in social skills and communication, as well as in repetitive and restricted behaviors, with onset occurring prior to age 3. Abnormal brain development, probably beginning prenatally, is known to be fundamental to the behaviors that characterize autism. Current estimates place the condition’s incidence at between 1 in 100 and 1 in 110 children in the United States.

Children with a sibling already diagnosed with autism are known to be among those at greatest risk of developing the disorder. The current study included 25 high-risk children who met criteria for autism at 3 years of age, matched with 25 low risk peers who were developing normally. It was conducted at the MIND Institute and the University of California, Los Angeles. The sole inclusion criterion for the high-risk group was having a sibling with autism; low-risk participants had to have been born after 36 weeks gestation and have no autistic family members.

The children’s development was evaluated at 6, 12, 18, 24 and 36 months of age using a series of widely implemented diagnostic tools, including the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). Examiners were not told which babies were at high- or low-risk when evaluating the participants’ development.

The researchers found that there were few discernable differences between the two groups at the outset but that after six months, 86 percent of the infants who developed autism showed declines in social communication that were outside the range for typical development. “After six months,” the study found, “the autism spectrum disorder group showed a rapid decline in eye contact, social smiling, and examiner-rated social responsiveness.” Group differences were significant by 12 months in eye contact and social smiling and all other measures by 18 months, the study found.

The study is notable because of the accuracy and precision of its prospective methodology, assiduously recording exact numbers of social and communicative behaviors during lab visits. Previously, researchers have constructed evidence of autism’s earliest manifestations by interviewing parents about when they believed their children’s symptoms first arose or by reviewing home movies for clues to when children begin exhibiting symptoms of autism.

“Until now, research has relied on asking parents when their child reached developmental milestones. But that can be really difficult to recall, and there is a phenomenon called the “telescoping effect” where people usually say that they remember something happening more recently than when it occurred,” Ozonoff said. In addition parents frequently will turn off the video camera when their children are behaving poorly — precisely when autistic symptoms may appear.

Ozonoff said that the study provides a deeper understanding for parents, caregivers and health-care providers and for future research of the developmental trajectory for very young children with autism.

“We need to be careful about how we screen, and we need to know what we’re looking for,” Ozonoff said. “This study tells us that screening for autism early in the first year of life probably is not going to be successful because there isn’t going to be anything to notice. It also tells us that we should be focusing on social behaviors in our screening, since that is what declines early in life.”

“This study also found that the loss of skills continues into the second and third year of life,” she said. “So it may not be adequate, as the American Academy of Pediatrics currently suggests, that providers screen for autism twice before the end of the second year. Autism has a slow, gradual onset of symptoms, rather than a very abrupt loss of skills.”

“Screening may need to continue into the third year of life, since symptom emergence takes place over a long time. If a child starts exhibiting a declining trajectory and a sustained reduction in social communication we want to refer them into therapy, especially if they are at risk,” Ozonoff said, “even before we might be able to make a definitive diagnosis.”

Ozonoff said that the study does not address the etiology of autism or causality. In this study, the infants who participated were at high risk due to having strong family histories of autism, suggesting that genetics play a major role in the later autism diagnoses, despite the fact that their symptoms were not apparent at birth.

Other study authors include Ana-Maria Iosif, Fam Baguio, Ian C. Cook, Monique Moore Hill, Mary Beth Steinfeld, Sally J. Rogers, Sarabjit Sangha and Gregory S. Young of UC Davis and Ted Hutman, Agata Rozga and Marian Sigman of the University of California, Los Angeles.

The study was funded by grants from the National Institute of Mental Health of the National Institutes of Health.

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Adapted from materials provided by University of California – Davis – Health System.

ScienceDaily (Feb. 18, 2010) ? Every moment of every day the brain is forced to process thousands of separate odorants from the world around us.

Through a new study of honeybees, scientists at UQ’s Queensland Brain Institute have discovered the brain has an advanced ability to isolate specific odours and recollect smells.

“There’s a lot of information coming into the brain whenever a scent is detected and it would be difficult to process it all,” lead researcher Dr Judith Reinhard said.

“We’ve found that honeybees pick only a handful of so-called ‘key odorants’ out of every complex aroma that they really learn. They may remember just two or three odorants from a couple of hundred, the rest are ignored.”

Colleague Dr Charles Claudianos said if you had to learn the hundreds of compounds your brain would be overwhelmed with information.

“By choosing the key odorants, you can function more effectively without being swamped,” Dr Charles Claudianos said.

The research, published in the latest edition of PLoS ONE, has also allowed the scientists to explore how the learning of odours affects molecules that have been linked to autism and schizophrenia. During their studies, the researchers found that the honeybee brain responds to sensory experience.

“The honeybee brain — like the human brain — adapts to its sensory environment by adjusting the expression of these molecules,” Dr Claudianos said.

Dr Reinhard said the findings could also have an enormous impact on Australian farming. Using the honeybee’s capacity to extract key odorants, scientists will be able to isolate these odorants from the complex aromas of crops. They can then use the key odorants to train honeybees to pollinate specific crops.

“Farmers often have problems making honeybees focus on the crop — the bees go astray and go to nearby forests or national parks and the farmers don’t get a good yield,” Dr Reinhard said.

“If we know the key odorants of the almond aroma, for example, we could use these to train the honeybees in the hive to focus only on pollinating almonds. Then you’d have a much higher likelihood the honeybees would stay in the crop and pollinate it.”

Now the focus for the QBI scientists will be whether humans use the same technique of learning specific key odorants so our brain is not overwhelmed by too much sensory information — early research suggests we do.

Story Source:

Adapted from materials provided by University of Queensland.

Journal Reference:

1. Reinhard et al. Honeybees Learn Odour Mixtures via a Selection of Key Odorants. PLoS ONE, 2010; 5 (2): e9110 DOI: 10.1371/journal.pone.0009110

ScienceDaily (Feb. 24, 2010) ? A genetic link between schizophrenia and autism is enabling researchers to study the effectiveness of drugs used to treat both illnesses.

Dr Steve Clapcote from the University of Leeds’s Faculty of Biological Sciences will be analysing behaviour displayed by mice with a genetic mutation linked to schizophrenia and autism and seeing how antipsychotic drugs affect their behavioural abnormalities.

“We don’t fully understand how the drugs used to treat schizophrenia and some symptoms of autism work,” explained Dr Clapcote. “If we can show they can affect mice with this particular genetic mutation, then it gives us a clue to better understand the illnesses and opens up the possibility of more targeted treatments with fewer side effects.”

A number of autism and schizophrenia patients have been found to have mutations of neurexin 1a, a protein which helps to form and maintain nerve signals in the brain. Scientists in the USA recently discovered that mice with the same genetic mutation display behavioural abnormalities which are consistent with schizophrenia and autism.

Dr Clapcote is planning to build on these initial findings to provide further evidence for a genetic link to the conditions. He also aims to assess the impact on the mice of antipsychotic drugs used to treat schizophrenia and some symptoms of autism.

“The genetic studies so far are suggesting a common cause for both schizophrenia and autism, which is something our studies will help to establish,” said Dr Clapcote. “However, these illnesses are complex, involving not only inheritance, but other factors such as environment and experience. It’s possible the genetic mutation might create a predisposition, making people more likely to develop autism or schizophrenia.”

The mice will be run through a series of tests designed to assess behaviour related to autism and/or schizophrenia: hyperactivity, sensitivity to psychostimulants, attention levels, memory, social interaction and learning. Dr Clapcote will also look at verbal communication — using bat recorders to ‘listen’ to the interaction between the mice which takes place beyond the range of human hearing.

“Behaviour is the final output of the nervous system and the means by which autism and schizophrenia are diagnosed, which is why our research focuses on behaviour,” said Dr Clapcote. “Schizophrenia and autism patients both display lower levels of verbal communication and we hope to see this mirrored in the mice we’re working with.”

The two-year project has been funded by a ?250,000 grant from the Medical Research Council. If the research proves successful, Dr Clapcote plans to investigate a proposed link between neurexin 1a and nicotine dependence, as a possible explanation for why a large percentage of schizophrenia patients become dependent on tobacco.

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Adapted from materials provided by University of Leeds.

ScienceDaily (Feb. 24, 2010) ? When a gene implicated in human autism is disabled in mice, the rodents show learning problems and obsessive, repetitive behaviors, researchers at UT Southwestern Medical Center have found.

The researchers also report that a drug affecting a specific type of nerve function reduced the obsessive behavior in the animals, suggesting a potential way to treat repetitive behaviors in humans. The findings appear in the Feb. 24 issue of the Journal of Neuroscience.

“Clinically, this study highlights the possibility that some autism-related behaviors can be reversed through drugs targeting specific brain function abnormalities,” said Dr. Craig Powell, assistant professor of neurology and psychiatry at UT Southwestern and the study’s senior author.

“Understanding one abnormality that can lead to increased, repetitive motor behavior is not only important for autism, but also potentially for obsessive-compulsive disorder, compulsive hair-pulling and other disorders of excessive activity,” Dr. Powell said.

The study focused on a protein called neuroligin 1, or NL1, which helps physically hold nerve cells together so they can communicate better with one another. Mutations in proteins related to NL1 have been implicated in previous investigations to human autism and mental retardation.

In the latest study, the UT Southwestern researchers studied mice that had been genetically engineered to lack NL1. These mice were normal in many ways, but they groomed themselves excessively and were not as good at learning a maze as normal mice.

The altered mice showed weakened nerve signaling in a part of the brain called the hippocampus, which is involved in learning and memory, and in another brain region involved in grooming.

When treated with a drug called D-cycloserine, which activates nerves in those brain regions, the excessive grooming lessened.

“Our goal was not to make an ‘autistic mouse’ but rather to understand better how autism-related genes might alter brain function that leads to behavioral abnormalities,” Dr. Powell said. “By studying mice that lack neuroligin-1, we hope to understand better how this molecule affects communication between neurons and how that altered communication affects behavior.

“This study is important because we were able to link the altered neuronal communication to behavioral effects using a specific drug to ‘treat’ the behavioral abnormality.”

Future studies, Dr. Powell said, will focus on understanding in more detail how NL1 operates in nerve cells.

Other UT Southwestern researchers participating in the study were co-lead authors Jacqueline Blundell, former postdoctoral researcher in neurology, and Dr. Cory Blaiss, postdoctoral researcher in neurology; Felipe Espinosa, senior research scientist in neurology; and graduate student Christopher Walz.

Researchers at Stanford University also contributed to this work.

The research was supported by Autism Speaks, the Simons Foundation, the National Institute of Mental Health, BRAINS for Autism, and the Hartwell Foundation.

Story Source:

Adapted from materials provided by UT Southwestern Medical Center.

Journal Reference:

1. Jacqueline Blundell, Cory A. Blaiss, Mark R. Etherton, Felipe Espinosa, Katsuhiko Tabuchi, Christopher Walz, Marc F. Bolliger, Thomas C. S?dhof, and Craig M. Powell. Neuroligin-1 Deletion Results in Impaired Spatial Memory and Increased Repetitive Behavior. Journal of Neuroscience, 2010; 30 (6): 2115 DOI: 10.1523/JNEUROSCI.4517-09.2010