1. Berman RF, Murray KD, Arque G, Hunsaker MR, Wenzel HJ. {{Abnormal dendrite and spine morphology in primary visual cortex in the CGG knock-in mouse model of the fragile X premutation}}. {Epilepsia};2012 (Jun);53 Suppl 1:150-160.
The fragile X mental retardation 1 gene (Fmr1) is polymorphic for CGG trinucleotide repeat number in the 5′-untranslated region, with repeat lengths <45 associated with typical development and repeat lengths >200 resulting in hypermethylation and transcriptional silencing of the gene and mental retardation in the fragile X Syndrome (FXS). Individuals with CGG repeat expansions between 55 and 200 are carriers of the fragile X premutation (PM). PM carriers show a phenotype that can include anxiety, depression, social phobia, and memory deficits. They are also at risk for developing fragile X-associated tremor/ataxia syndrome (FXTAS), a late onset neurodegenerative disorder characterized by tremor, ataxia, cognitive impairment, and neuropathologic features including intranuclear inclusions in neurons and astrocytes, loss of Purkinje cells, and white matter disease. However, very little is known about dendritic morphology in PM or in FXTAS. Therefore, we carried out a Golgi study of dendritic complexity and dendritic spine morphology in layer II/III pyramidal neurons in primary visual cortex in a knock-in (KI) mouse model of the PM. These CGG KI mice carry an expanded CGG trinucleotide repeat on Fmr1, and model many features of the PM and FXTAS. Compared to wild-type (WT) mice, CGG KI mice showed fewer dendritic branches proximal to the soma, reduced total dendritic length, and a higher frequency of longer dendritic spines. The distribution of morphologic spine types (e.g., stubby, mushroom, filopodial) did not differ between WT and KI mice. These findings demonstrate that synaptic circuitry is abnormal in visual cortex of mice used to model the PM, and suggest that such changes may underlie neurologic features found in individuals carrying the PM as well as in individuals with FXTAS.
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2. Casanova JR, Nishimura M, Owens JW, Swann JW. {{Impact of seizures on developing dendrites: Implications for intellectual developmental disabilities}}. {Epilepsia};2012 (Jun);53 Suppl 1:116-124.
Childhood epilepsy can be severe and even catastrophic. In these instances, cognition can be impaired-leading to long-term intellectual disabilities. One factor that could potentially cause cognitive deficits is the frequent seizures that characterize intractable epilepsy. However, it has been difficult to separate the effects seizures may have from those of preexisting neuropathologies and/or the effects of ongoing anticonvulsant therapies. Therefore, important questions are: Do early life seizures produce the learning deficits? And if they do, how do they do it? Results from recent animal models studies reviewed here show that recurrent seizures in infancy stop the growth of CA1 hippocampal dendrites. We speculate that the molecular mechanisms responsible for seizure-induced growth suppression are homeostatic/neuroprotective, used by the developing nervous system in an attempt to limit neuronal and network excitability and prevent the continued generation of seizures. However, by preventing the normal growth of dendrites, there is a reduction in CA1 glutamatergic synapses that supports long-lasting forms of synaptic plasticity thought to be the cellular basis of learning and memory. Therefore, dendrite growth suppression would reduce the neuroanatomic substrates for learning and memory, and in so doing could contribute in important ways to spatial learning and memory deficits that may be relevant to the cognitive deficits associated with childhood epilepsy.
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3. Hall D, Huerta MF, McAuliffe MJ, Farber GK. {{Sharing Heterogeneous Data: The National Database for Autism Research}}. {Neuroinformatics};2012 (May 24)
The National Database for Autism Research (NDAR) is a secure research data repository designed to promote scientific data sharing and collaboration among autism spectrum disorder investigators. The goal of the project is to accelerate scientific discovery through data sharing, data harmonization, and the reporting of research results. Data from over 25,000 research participants are available to qualified investigators through the NDAR portal. Summary information about the available data is available to everyone through that portal.
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4. Morgan JT, Chana G, Abramson I, Semendeferi K, Courchesne E, Everall IP. {{Abnormal microglial-neuronal spatial organization in the dorsolateral prefrontal cortex in autism}}. {Brain Res};2012 (May 25);1456:72-81.
Microglial activation and alterations in neuron number have been reported in autism. However, it is unknown whether microglial activation in the disorder includes a neuron-directed microglial response that might reflect neuronal dysfunction, or instead indicates a non-directed, pro-activation brain environment. To address this question, we examined microglial and neuronal organization in the dorsolateral prefrontal cortex, a region of pronounced early brain overgrowth in autism, via spatial pattern analysis of 13 male postmortem autism subjects and 9 controls. We report that microglia are more frequently present near neurons in the autism cases at a distance interval of 25mum, as well as 75 and 100mum. Many interactions are observed between near-distance microglia and neurons that appear to involve encirclement of the neurons by microglial processes. Analysis of a young subject subgroup preliminarily suggests that this alteration may be present from an early age in autism. We additionally observed that neuron-neuron clustering, although normal in cases with autism as a whole, increases with advancing age in autism, suggesting a gradual loss of normal neuronal organization in the disorder. Microglia-microglia organization is normal in autism at all ages, indicating that aberrantly close microglia-neuron association in the disorder is not a result of altered microglial distribution. Our findings confirm that at least some microglial activation in the dorsolateral prefrontal cortex in autism is associated with a neuron-specific reaction, and suggest that neuronal organization may degrade later in life in the disorder.
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5. Neal D, Matson JL, Belva BC. {{Discriminant analysis of the autism spectrum disorder observation for children}}. {Dev Neurorehabil};2012 (May 25)
Purpose: To run a discriminant analysis on the individual items and the total scale of the ASD-OC to determine if they significantly discriminated between ASD and atypical groups. Method: The measure was administered to 78 children as part of an outpatient evaluation. Results: The DA revealed that all of the items, excluding five, were significant predictors by themselves. Additionally, Wilks’ lambda was significant, lambda = 0.16, chi(2 )= 115.91, p < 0.001 for the function, indicating that all of the items together significantly discriminated between groups. The DA was run again excluding those items mentioned above and the variability accounted for by all of the items and prediction of group membership decreased. Therefore, all 45 items were retained for inclusion in the final version of the ASD-OC. Conclusion: The ASD-OC is able to discriminate between ASD and atypical groups.
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6. Stefani A, Brusa L, Olivola E, Pierantozzi M, Martorana A. {{CSF and clinical hallmarks of subcortical dementias: focus on DLB and PDD}}. {J Neural Transm};2012 (May 24)
Dementia has become a relevant problem associated with the elderly in our countries. Increased interest in the field has yielded a copious literature, so far mostly centered on Alzheimer’s dementia. Cerebrospinal fluid (CSF) analysis combined with neuropsychology, even in absence of neuroimaging, represents the gold standard to reach a diagnosis when cortical cognitive impairment prevails. In view of this, low levels of CSF amyloid peptides beta (Abeta) and high tau/Abeta protein ratio, despite prominent impairment of executive functions or concomitant vascular burden, facilitate the diagnosis of Alzheimer’s disease. Conversely, an early cognitive impairment occurring in patients suffering from Parkinson’s disease (PD) or Lewy body disorders (LBDs), both diagnoses posed on pure clinical grounds, remains quite elusive in term of biomarkers or neuropsychological assessment. Whether PD with dementia (PDD) and dementia with Lewy bodies (DLB) represent further steps along with a continuum of the same progressive degeneration due to Lewy bodies deposition, rather then the association of Lewy bodies and Abeta pathology, remains a challenging issue. Aim of this work is to set a state-of-the-art on the neuropsychological profiles of both or DLB. Then, we will focus on the ongoing controversies about the specificity of the standard CSF biomarkers if applied to extrapyramidal disorders. Our conclusions are that the CSF pattern, in PDD and DLB, can certainly be distinct from that in AD, though mechanisms leading to dementia could be shared among them. It is possible that, by combining imaging tracers, neuropsychologically careful assessment and renewed CSF biomarkers, DLB can be better distinguished in subgroups, depending on the presence or absence of a relevant amyloid burden. However, more complete data, possibly collected in fieri during the progressive derangement of cognitive abilities, are needed to improve our ability to decipher and treat these entities.
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7. Yanardag M, Akmanoglu N, Yilmaz I. {{The effectiveness of video prompting on teaching aquatic play skills for children with autism}}. {Disabil Rehabil};2012 (May 25)
Objective: To investigate the effectiveness of the video prompting procedure on teaching aquatic play skills and to determine the effects of aquatic exercise training on the motor performance of children with autism. Design: A multiple probe design across behaviours was used and replicated across subjects for the instructional part of this study. Pretest-posttest design was applied for the exercise training part of this study. Methods: Three children with autism were taught three aquatic play skills in a one-to-one training format. Aquatic play skills intervention and aquatic exercise training were performed separately throughout 12 weeks at three sessions per week, each lasting 1 h. The video prompting procedure was utilized for the instruction part of this study. Results: Video prompting was effective in teaching aquatic play skills to children with autism. In addition, aquatic exercise training increased the total motor performance scores of all the participants after 12 weeks. According to the social validity results, the families gave positive feedback about the learned skills and movement capabilities of their children. Conclusion: Aquatic play skills and swimming pools are favoured for children with autism. This attractive intervention is recommended as a means to extend knowledge of leisure skills and motor development of children with autism. [Box: see text].
