Unusually high levels of the signaling peptide BDNF, or brain-derived neurotrophic factor, have been detected in blood samples from children with autism. Barbara Hempstead of Weill Medical College at Cornell University and her colleagues propose that BDNF may also be over-expressed in the brains of these children, causing neurological defects that lead to the disorder.
Fever has benefits beyond its role in fighting infection. According to a prospective study published in 2007 and to many anecdotal reports, fever can improve cognitive function and behavior in individuals with autism.
Several studies have shown that a micro-duplication within 15q11-13 — a region on chromosome 15 — on the maternal chromosome is associated with autism. The duplicated region contains many genes, but UBE3A, which encodes a ubiquitin ligase, deserves special attention because duplications apparently restricted to the UBE3A gene have been found in people with autism.
Preliminary studies suggest that the so-called ‘love hormone’ oxytocin could improve some of the social deficits characteristic of people with autism. On 11 April, SFARI hosted a workshop to explore oxytocin’s relationship to social behavior and its potential as a therapy for autism.
Researchers can use biomarkers to diagnose individuals with autism and to hone in on the underlying causes of the disorder. In July, SFARI held an informal meeting of minds at Stony Brook University to discuss biomarkers for autism.
Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by impairments in social interaction and communication, and restricted, stereotyped behaviors that manifest in early childhood. Research findings have identified widespread changes in the immune system in children with autism.
Perturbed neuronal arborization, or branching, and defects in long-range connectivity are likely to be shared mechanisms in many forms of severe autism. Neurotrophic factors (proteins that play a role in the growth and maintenance of neurons) and their cognate receptors, such as brain-derived neurotrophic factor (BDNF) and TrkB, respectively, govern the development of neuronal circuitry, in part, through signaling at the level of intracellular organelles known as endosomes. The protein NHE6 localizes within the cell membranes that form endosomes. Moreover, through its role in mediating the transport of protons (H+) out of endosomes in exchange for the import of sodium (Na+) ions, it contributes to modulating endosome acidity.
A hallmark of autism is impairment in reciprocal social interaction, including inadequate eye contact and failure to recognize emotions. Research shows that the neuropeptide oxytocin modulates social behavior. In mice, rats, monkeys and sheep, for instance, administration of oxytocin enhances social recognition, memory of peers, and development of partner preference and bonding. In people, including those with autism, oxytocin nasal spray can significantly enhance social cognition.
Attentional deficits are a major cause of disability in individuals with autism. Recently, Vikaas Sohal and colleagues described a possible circuit mechanism contributing to attentional deficits in autism[ref]Luongo F.J. et al. Biol. Psychiatry 79, 667-675 (2016) PubMed[/ref]. For the current project, Sohal proposes to identify a specific cellular locus underlying these circuit abnormalities.
Most individuals with autism experience at least one form of hypersensitivity from the five senses. These alterations in sensory-related behaviors can lead to profound limitations on an individual’s ability to work, interact with family and participate in leisure activities. Furthermore, these atypical responses to otherwise normal sensory stimuli may be closely associated with the core symptoms of autism, such as social deficits and repetitive behaviors. Despite the importance of sensory abnormalities in the pathogenesis of autism, how the brains of individuals with autism receive information from the five senses at the subcortical level and how such information becomes transformed into aversive responses has not been investigated.
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