Brain Development

Unreliable Evoked Responses in Autism

Source: 
Neuron
Date Published: 
September 20, 2012
Abstract: 

This imaging study led by Carnegie Mellon researchers suggests adults with autism have unreliable neural responses when presented with basic sensory information.

University says findings could bring us closer to understanding the connection between brain and behavior in autism. See the press release here: http://www.cmu.edu/news/stories/archives/2012/september/sept19_autisticn...

Announcing the Autism Brain Imaging Data Exchange, a Database of Brain Scans from Over 15 Medical and Research Institutions Worldwide

Source: 
Enhanced Online News
Date Published: 
September 24, 2012
Abstract: 

Researchers officially announce the creation of the Autism Brain Imaging Data Exchange, a database of previously collected brain scans from over 15 medical and research institutions worldwide. The founders aim to advance scientific understanding of ASD through this data sharing initiative.

Shared Synaptic Pathophysiology in Syndromic and Nonsyndromic Rodent Models of Autism

Source: 
Science
Date Published: 
September 13, 2012
Abstract: 

A new study finds that faulty neuronal circuits in autistic brains can be corrected even after the “critical window” of brain development.

Molecular Mechanisms: Autism Gene Regulates Neuron Shape

Source: 
Simons Foundation Austism Research Initiative
Date Published: 
July 31,2012
Abstract: 

Scientists at MIT have found that TAOK2, a gene in the autism-associated chromosomal region, is part of a signaling pathway that builds neuronal connections during development.

Simple Worms could Help Unravel Complex Human Brains

Source: 
Simons Foundation Austism Research Initiative
Date Published: 
July 25, 2012
Abstract: 

The nematode "Caenorhabditis elegans" may serve as a useful model to study synapses, the junctions between neurons.

Vanderbilt University Study Measures Attention to Changing Facial Features in High-Risk Infants

Source: 
Autism Research
Date Published: 
June 1, 2012
Abstract: 

Study from Vanderbilt University uses eye-tracking and visual event-related potentials to measure attention to changing facial features in infants at high-risk for developing autism.

Seizures in Angelman Syndrome Could be Linked to an Imbalance in Brain Activity

Source: 
UNC School of Medicine
Date Published: 
June 6, 2012
Abstract: 

Researchers led by Dr. Ben Philpot, an ASF funded mentor, at UNC School of Medicine found that seizures in individuals with Angelman syndrome could be linked to an imbalance in brain cell activity. Angelman syndrome exhibits frequent comorbidity with autism spectrum disorders.

Newly Published Genetics/Brain Tissue Study Will Help Refine the Search for Specific Early Genetic Markers of Risk of Autism in Babies and Toddlers

Source: 
PLoS Genetics
Date Published: 
March 22, 2012
Year Published: 
2012
Abstract: 

A new study of autism published today in PLoS Genetics has discovered abnormal gene activity and gene deletions in the same brain region that also has a 67% overabundance of brain cells. This region – the prefrontal cortex—is involved in social, emotional, communication and language skills. The finding brings new understanding of what early genetic abnormalities lead to excess brain cells and to the abnormal brain wiring that cause core symptoms in autism. Importantly, the study also shows that gene activity abnormalities in autism change across the lifespan.

By Dr. Eric Courchesne

A new study of autism published today in PLoS Genetics (Age Dependent Brain Gene Expression and Copy Number Anomalies in Autism Suggest Distinct Pathological Processes at Young Versus Mature Ages) has discovered abnormal gene activity and gene deletions in the same brain region that also has a 67% overabundance of brain cells.  This region – the prefrontal cortex—is involved in social, emotional, communication and language skills. The finding brings new understanding of what early genetic abnormalities lead to excess brain cells and to the abnormal brain wiring that cause core symptoms in autism. Importantly, the study also shows that gene activity abnormalities in autism change across the lifespan.

The research is one of the first to focus on gene activity inside the young autistic brain, and is the first to examine how gene expression activity changes across the lifespan in autism.  It is also one of the largest postmortem studies of autism to date. This close-up look inside the brain uncovered the presence of abnormal levels of activity in genes (“gene expression”) and gene defects (deletions of portions of DNA sequences) that control the number of brain cells and their growth and pattern of organization in the developing prefrontal cortex. The abnormal gene activity occurred in several networks that are important during prenatal brain development (cell cycle, neurogenesis, DNA damage detection and response, apoptosis and survival networks). This seems to rule out a number of current speculations about postnatal causes of autism and, combined with the new evidence of a 67% excess of prefrontal brain cells, points instead to prenatal causal events in a majority of cases.

The study’s direct examination of both mRNA and DNA from the same frontal cortex region in each individual is also a unique approach to discovering the genetics of abnormal brain development in autism.  The combined mRNA and DNA results indicate that a large and heterogeneous array of gene and gene expression defects disrupt prenatal processes that are critical to early prefrontal cortex formation. “Although DNA defects vary from autistic case to case, the diverse genetic deletions seem to underlie a relatively common biological theme, hitting a shared set of gene pathways that impact cell cycle, DNA damage detection and repair, migration, neural patterning and cell differentiation,” according to the study.  Importantly, the set of functional gene pathways identified by the study’s direct analyses of autistic brain tissue are consistent with those identified by previous studies that analyzed copy number variations in living autistic patients.

A second major discovery in this study is that the pattern of abnormal gene activity changes across the lifespan in autism. Thus, in adults with autism, the study found abnormal activity in genes involved in remodeling, repair, immune response and signaling. This raises opportunities for new research directions that ask whether and how such later alterations in genetic activity impact brain structure and function.  A hope is that perhaps this later, second stage of unusual genetic activity we detected in adults with autism has something to do with enhancing adaptive connections and pruning back earlier maladaptive connections.  Further research needs to better understand the impact of those later changes in genetic activity.

Findings in the new study will help refine the search for specific early genetic markers of risk of autism in babies and toddlers.  Next steps include identifying what causes the altered genetic activity at early stages of development, when nerve cells in prefrontal cortex arise and the first steps in creating brain circuitry are being taken.  Knowledge of these specific patterns of abnormal gene activity may also give rise to future studies that search for medical interventions that target abnormal gene activity in an age-specific fashion.

New Autism Research Reveals Brain Differences at 6 Months in Infants Who Develop Autism

Source: 
Center for Autism Research at The Children's Hospital of Philadelphia (CHOP)
Date Published: 
February 17, 2012
Abstract: 

A new study from the Infant Brain Imaging Network, which includes researchers at the Center for Autism Research at The Children's Hospital of Philadelphia (CHOP), found significant differences in brain development starting at age 6 months in high-risk infants who later develop autism, compared to high-risk infants who did not develop autism.

Mental Illness Suspect Genes Found To Be Among The Most Environmentally Responsive By NIH Study

Source: 
Medical News Today
Date Published: 
February 6, 2012
Abstract: 

For the first time, scientists have tracked the activity, across the lifespan, of an environmentally responsive regulatory mechanism that turns genes on and off in the brain's executive hub.