1. Church BA, Rice CL, Dovgopoly A, Lopata CJ, Thomeer ML, Nelson A, Mercado E, 3rd. {{Learning, plasticity, and atypical generalization in children with autism}}. {Psychonomic bulletin & review}. 2015 Jan 6.
Individuals with autism spectrum disorder (ASD) show accelerated learning in some tasks, degraded learning in others, and distinct deficits when generalizing to novel situations. Recent simulations with connectionist models suggest that deficits in cortical plasticity mechanisms can account for atypical patterns of generalization shown by some children with ASD. We tested the surprising theoretical prediction, from past simulations, that the children with ASD who show atypical generalization in perceptual categorization tasks will benefit more from training with a single prototypical member of the category than from training with multiple examples, but children with ASD who generalize normally will be comparatively harmed. The experimental results confirmed this prediction, suggesting that plasticity deficits may well underlie the difficulties that some children with ASD have generalizing skills, and these deficits are not specific to the acquisition of social skills, but rather reflect a more general perceptual learning deficit that may impact many abilities.
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2. Gallagher D, Voronova A, Zander MA, Cancino GI, Bramall A, Krause MP, Abad C, Tekin M, Neilsen PM, Callen DF, Scherer SW, Keller GM, Kaplan DR, Walz K, Miller FD. {{Ankrd11 Is a Chromatin Regulator Involved in Autism that Is Essential for Neural Development}}. {Developmental cell}. 2014 Dec 30.
Ankrd11 is a potential chromatin regulator implicated in neural development and autism spectrum disorder (ASD) with no known function in the brain. Here, we show that knockdown of Ankrd11 in developing murine or human cortical neural precursors caused decreased proliferation, reduced neurogenesis, and aberrant neuronal positioning. Similar cellular phenotypes and aberrant ASD-like behaviors were observed in Yoda mice carrying a point mutation in the Ankrd11 HDAC-binding domain. Consistent with a role for Ankrd11 in histone acetylation, Ankrd11 was associated with chromatin and colocalized with HDAC3, and expression and histone acetylation of Ankrd11 target genes were altered in Yoda neural precursors. Moreover, the Ankrd11 knockdown-mediated decrease in precursor proliferation was rescued by inhibiting histone acetyltransferase activity or expressing HDAC3. Thus, Ankrd11 is a crucial chromatin regulator that controls histone acetylation and gene expression during neural development, thereby providing a likely explanation for its association with cognitive dysfunction and ASD.
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3. Heyman M, Hauser-Cram P. {{Negative life events predict performance on an executive function task in young adults with developmental disabilities}}. {Journal of intellectual disability research : JIDR}. 2015 Jan 6.
BACKGROUND: Recent research with typically developing children indicates that chronic stress can be detrimental to the development of executive function. This study extends this work to individuals with developmental disabilities and examines the longitudinal relationship between an indicator of chronic stress, negative life events, and performance on a task of executive function within a group of 30 individuals with early identified developmental disabilities. METHODS: Multilevel modelling was used to analyse the relationship between cumulative negative life events and response time on a Flanker task. RESULTS: As hypothesized, individuals who had experienced more cumulative negative life events in their families demonstrated longer response time, an indicator of less efficient executive function. CONCLUSIONS: The association between cumulative negative life events and executive function for children with developmental disabilities suggests the prominent role of the environment for development in this domain. These findings also suggest the importance of providing services, resources, and interventions that will help families adaptively cope with stressful circumstances.
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4. Karp EA, Kuo AA. {{Maternal mental health after a child’s diagnosis of autism spectrum disorder}}. {Jama}. 2015 Jan 6;313(1):81-2.
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5. Ross JL, Tartaglia N, Merry DE, Dalva M, Zinn AR. {{Behavioral Phenotypes In Males With XYY and Possible Role of Increased NLGN4Y Expression in Autism Features}}. {Genes, brain, and behavior}. 2015 Jan 6.
INTRODUCTION: The male sex chromosome disorder 47,XYY syndrome (XYY) is associated with increased risk for social-emotional difficulties, attention deficit (ADHD), and autism spectrum disorders (ASD). We hypothesize that increased Y chromosome gene copy number in XYY leads to overexpression of Y-linked genes related to brain development and function, thereby increasing risk for these phenotypes. METHODS: We measured expression in blood of two Y genes NLGN4Y and RPS4Y in 26 boys with XYY and 11 male controls and evaluated whether NLGN4Y expression correlates with anxiety, ADHD, depression, and autistic behaviors (from questionnaires) in boys with XYY. RESULTS: The XYY cohort had increased risk of ASD behaviors on the Social Responsiveness Scale (SRS) and increased attention deficits on the Conners’ DSM-IV Inattention and Hyperactive scales. In contrast, there was no increase in reported symptoms of anxiety or depression by the XYY group. Peripheral expression of two Y genes in boys with XYY versus TD controls was increased two-fold in the XYY group. Results from the SRS Total and Autistic Mannerisms scales but not the attention, anxiety or depression measures correlated with peripheral expression of NLGN4Y in boys with XYY. CONCLUSIONS: Males with XYY have social phenotypes that include increased risk for autism related behaviors and ADHD. Expression of NLGN4Y, a gene that may be involved in synaptic function, is increased in boys with XYY, and the level of expression correlates with overall social responsiveness and autism symptoms. Thus, further investigation of NLGN4Y as a plausible ASD risk gene in XYY is warranted.
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6. Schauder KB, Muller CL, Veenstra-VanderWeele J, Cascio CJ. {{Genetic Variation in Serotonin Transporter Modulates Tactile Hyperresponsiveness in ASD}}. {Research in autism spectrum disorders}. 2015 Feb 1;10:93-100.
Several lines of evidence implicate dysfunction of the serotonin (5-HT) system in autism spectrum disorder (ASD). Specifically, the serotonin transporter (5-HTT, SERT) has been scrutinized as an ASD candidate risk gene. SERT plays key roles in the development of circuits that underlie sensory function, particularly in the somatosensory system. One previous study in ASD found association of a rare, hyperfunctional SERT variant with sensory aversion, but studies of common SERT variants have never examined sensory symptoms in ASD. Using standardized caregiver assessments of sensory function in children, we evaluated patterns of sensory responsiveness in 47 children with ASD and 38 typically developing (TD) children. Study participants were genotyped for the functional SERT promoter polymorphisms, 5-HTTLPR and rs25531, to test the hypothesis that the higher expressing genotypes would be associated with hyperresponsiveness to touch, a common sensory aversion in ASD. All measures of sensory hypo- and hyperresponsiveness were increased in children with ASD, with hyporesponsive sensory patterns negatively correlated to age and hyperresponsive sensory patterns positively correlated to repetitive behavior. Strikingly, high-expressing SERT genotypes were associated with increased tactile hyperresponsiveness in the ASD group. Our findings indicate genetic variation that increases SERT function may specifically impact somatosensory processing in ASD.
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7. Seo KH, Jung HS, Kang EG, Kim CJ, Rhee HY, Jeon YS. {{Sedation using 5% lidocaine patches, midazolam and propofol in a combative, obese adolescent with severe autistic disorder undergoing brain magnetic resonance imaging: a case report}}. {Korean journal of anesthesiology}. 2014 Dec;67(6):421-4.
We present a 17-year-old man who underwent brain magnetic resonance imaging and laboratory exams for uncontrolled seizure. Patients with an autistic disorder require deep sedation or, occasionally, general anesthesia even for radiologic exams or simple procedures. The anesthetic management of an obese, violent patient with a severe autistic disorder and mental retardation can be challenging to anesthesiologists and requires a more careful approach in selecting adequate anesthetics and doses. This case emphasizes the importance of having a detailed plan to ensure the smooth process of premedication, anesthetic induction, maintenance, emergence and safe discharge of incorporated patients in the event of unexpected situations. A 5% lidocaine patch to relieve the pain from the intramuscular injection and intravenous cannulation, intramuscular midazolam as premedication, and propofol for the maintenance of sedation can be a good sedation protocol in incorporated patients.
