Pubmed du 28/09/10

Pubmed du jour

2010-09-28 12:03:50

1. Bertone A, Hanck J, Kogan C, Chaudhuri A, Cornish K. {{Associating Neural Alterations and Genotype in Autism and Fragile X Syndrome: Incorporating Perceptual Phenotypes in Causal Modeling}}. {J Autism Dev Disord} (Sep 25)

We have previously described (see companion paper, this issue) the utility of using perceptual signatures for defining and dissociating condition-specific neural functioning underlying early visual processes in autism and FXS. These perceptually-driven hypotheses are based on differential performance evidenced only at the earliest stages of visual information processing, mediated by local neural network functioning. In this paper, we first review how most large-scale neural models are unable to address atypical low-level perceptual functioning in autism, and then suggest how condition-specific, local neural endophenotypes (described in our companion paper) can be incorporated into causal models to infer target candidate gene or gene clusters that are implicated in autism’s pathogenesis. The usefulness of such a translational research approach is discussed.

2. Murdock LC, Hobbs JQ. {{Picture Me Playing: Increasing Pretend Play Dialogue of Children with Autism Spectrum Disorders}}. {J Autism Dev Disord} (Sep 25)

This study examined the effectiveness of the Picture Me Playing intervention for increasing the play dialogue of preschool children with ASD during pretend play opportunities with typical peers. Picture Me Playing is a pictorially enhanced, script based intervention targeting character role play through a narrative vignette. A single-treatment counterbalanced design was utilized to contrast the performance of intervention and comparison groups, followed by within-subject analysis. Results indicated significant increases in play dialogue represented by both scripted and novel utterances. Results generalized to an unscripted play opportunity with novel toys.

3. Pierce K. {{Early functional brain development in autism and the promise of Sleep fMRI}}. {Brain Res} (Sep 23)

4. Schumann CM, Nordahl CW. {{Bridging the Gap between MRI and Postmortem Research in Autism}}. {Brain Res} (Sep 22)

Autism is clearly a disorder of neural development, but when, where, and how brain pathology occurs remains elusive. Typical brain development is comprised of several stages, including the proliferation and migration of neurons, creation of dendritic arbors and synaptic connections, and eventually dendritic pruning and programmed cell death. Any deviation at one or more of these stages could produce catastrophic downstream effects. MRI studies of autism have provided important clues, describing an aberrant trajectory of growth during early childhood that is both present in total brain and marked in specific structures such as the amygdala. However, given the coarse resolution of MRI, the field must also look towards postmortem human brain research to help elucidate the neurobiological underpinnings of MRI volumetric findings. Likewise, studies of postmortem tissue may benefit by looking to findings from MRI studies to narrow hypotheses and target specific brain regions. In this review, we discuss the strengths, limitations, and major contributions of each approach to autism research. We then describe how they relate and what they can learn from each other. Only by integrating these approaches will we be able to fully explain the neuropathology of autism.

5. Seno MM, Hu P, Gwadry FG, Pinto D, Marshall CR, Cassallo G, Scherer SW. {{Gene and miRNA Expression Profiles in Autism Spectrum Disorders}}. {Brain Res} (Sep 21)

Accumulating data indicate that there is significant genetic heterogeneity underlying the etiology in individuals diagnosed with autism spectrum disorder (ASD). Some rare and highly-penetrant gene variants and copy number variation (CNV) regions including NLGN3, NLGN4, NRXN1, SHANK2, SHANK3, PTCHD1, 1q21.1, maternally-inherited duplication of 15q11-q13, 16p11.2, amongst others, have been identified to be involved in ASD. Genome-wide association studies have identified other apparently low risk loci and in some other cases, ASD arises as a co-morbid phenotype with other medical genetic conditions (eg. fragile X). The progress studying the genetics of ASD has largely been accomplished using genomic analyses of germline-derived DNA. Here, we used gene and miRNA expression profiling using cell-line derived total RNA to evaluate possible transcripts and networks of molecules involved in ASD. Our analysis identified several novel dysregulated genes and miRNAs in ASD compared with controls, including HEY1, SOX9, miR-486 and miR-181b. All of these are involved in nervous system development and function and some others, for example, are involved in NOTCH signalling networks (eg. HEY1). Further, we found significant enrichment in molecules associated with neurological disorders such as Rett syndrome and those associated with nervous system development and function including long-term potentiation. Our data will provide a valuable resource for discovery purposes and for comparison to other gene expression-based, genome-wide DNA studies and other functional data.

6. Siman-Tov A, Kaniel S. {{Stress and Personal Resource as Predictors of the Adjustment of Parents to Autistic Children: A Multivariate Model}}. {J Autism Dev Disord} (Sep 25)

The research validates a multivariate model that predicts parental adjustment to coping successfully with an autistic child. The model comprises four elements: parental stress, parental resources, parental adjustment and the child’s autism symptoms. 176 parents of children aged between 6 to 16 diagnosed with PDD answered several questionnaires measuring parental stress, personal resources (sense of coherence, locus of control, social support) adjustment (mental health and marriage quality) and the child’s autism symptoms. Path analysis showed that sense of coherence, internal locus of control, social support and quality of marriage increase the ability to cope with the stress of parenting an autistic child. Directions for further research are suggested.

7. Wallace KS, Rogers SJ. {{Intervening in infancy: implications for autism spectrum disorders}}. {J Child Psychol Psychiatry} (Sep 24)

There is a scarcity of empirically validated treatments for infants and toddlers under age 3 years with autism spectrum disorders (ASD), as well as a scarcity of empirical investigation into successful intervention characteristics for this population. Yet early screening efforts are focused on identifying autism risk in children under age 3 years. In order to build ASD interventions for infants and toddlers upon a foundation of evidence-based characteristics, the current paper presents the results of a systematic literature search and effect size analysis of efficacious interventions for infants and toddlers with other developmental disorders: those who were born prematurely, have developmental impairments, or are at high risk for developmental impairments due to the presence of a biological or familial condition associated with developmental impairments. A review of 32 controlled, high-quality experimental studies revealed that the most efficacious interventions routinely used a combination of four specific intervention procedures, including (1) parent involvement in intervention, including ongoing parent coaching that focused both on parental responsivity and sensitivity to child cues and on teaching families to provide the infant interventions, (2) individualization to each infant’s developmental profile, (3) focusing on a broad rather than a narrow range of learning targets, and (4) temporal characteristics involving beginning as early as the risk is detected and providing greater intensity and duration of the intervention. These four characteristics of efficacious interventions for infants and toddlers with other developmental challenges likely represent a solid foundation from which researchers and clinicians can build efficacious interventions for infants and toddlers at risk for or affected by ASD.