1. Barttfeld P, Amoruso L, Ais J, Cukier S, Bavassi L, Tomio A, Manes F, Ibanez A, Sigman M. {{Organization of brain networks governed by long-range connections index autistic traits in the general population}}. {J Neurodev Disord};2013 (Jun 27);5(1):16.
BACKGROUND: The dimensional approach to autism spectrum disorder (ASD) considers ASD as the extreme of a dimension traversing through the entire population. We explored the potential utility of electroencephalography (EEG) functional connectivity as a biomarker. We hypothesized that individual differences in autistic traits of typical subjects would involve a long-range connectivity diminution within the delta band. METHODS: Resting-state EEG functional connectivity was measured for 74 neurotypical subjects. All participants also provided a questionnaire (Social Responsiveness Scale, SRS) that was completed by an informant who knows the participant in social settings. We conducted multivariate regression between the SRS score and functional connectivity in all EEG frequency bands. We explored modulations of network graph metrics characterizing the optimality of a network using the SRS score. RESULTS: Our results show a decay in functional connectivity mainly within the delta and theta bands (the lower part of the EEG spectrum) associated with an increasing number of autistic traits. When inspecting the impact of autistic traits on the global organization of the functional network, we found that the optimal properties of the network are inversely related to the number of autistic traits, suggesting that the autistic dimension, throughout the entire population, modulates the efficiency of functional brain networks. CONCLUSIONS: EEG functional connectivity at low frequencies and its associated network properties may be associated with some autistic traits in the general population.
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2. Edalatmanesh MA, Nikfarjam H, Vafaee-Bagheri F, Moghadas M. {{Increased Hippocampal Cell Density and Enhanced Spatial Memory in the Valproic Acid Rat Model of Autism}}. {Brain Res};2013 (Jun 24)
Autism is characterized by behavioral impairments in three main domains: social interaction; language, communication and imaginative play; and the range of interests and activities. However, neuronal processing studies have suggested that hyper-perception, hyper-attention, and enhanced memory, which may lie at the heart of most autistic symptoms. Pregnant Wistar rats were administered by either Valproic Acid (VPA, 500mg/kg) or Phosphate Buffer Saline (PBS) during fetal neural tube development on embryonic day 12.5. All offspring were subjected to various tests. The present study examined social interaction, repetitive behaviors, nociception and tactile threshold, anxiety as well as spatial memory. Histological analyses of cells in five regions of the hippocampus were done to determine neuronal density in both groups. A single intra-peritoneal injection of VPA to pregnant rats produced severe autistic-like symptoms in the offspring. The results showed significant behavioral impairments such as a lower tendency to initiate social interactions, enhanced stereotyped, repetitive behaviors, increased nociception threshold and anxiety at postnatal day (PND) 30 and PND 60. The Morris water maze learning paradigm revealed enhanced spatial memory at PND 60. Furthermore, histological analysis showed that the neuronal density in five separate regions of hippocampus (CA1, CA2, CA3, Dentate gyrus and Subiculum) were increased at PND 67. This work suggests that early embryonic exposure to VPA in rats provides a good model for several specific aspects of autism and should help to continue to explore pathophysiological and neuroanatomical hypotheses. This study provides further evidence to support the notion that spatial memory and hippocampal cell density are increased in this animal model of autism.
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3. Hendren RL. {{Autism: biomedical complementary treatment approaches}}. {Child Adolesc Psychiatr Clin N Am};2013 (Jul);22(3):443-456.
This article provides a conceptual overview for the use of biomedical complementary and alternative medicine (CAM) treatments for autism spectrum disorders. Pharmaceutical agents with published studies are briefly mentioned; but the focus of the article is on possible biomedical CAM treatments, the rationale for their use, and the current database of mostly preliminary studies regarding their safety and efficacy. Of the more than 50 treatments currently listed here and in use by eager families, 9 are reviewed in more detail because of their promise from preliminary research studies or because of public interest.
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4. Lauritsen MB, Astrup A, Pedersen CB, Obel C, Schendel DE, Schieve L, Yeargin-Allsopp M, Parner ET. {{Urbanicity and Autism Spectrum Disorders}}. {J Autism Dev Disord};2013 (Jun 27)
The etiology of autism spectrum disorders (ASD) is for the majority of cases unknown and more studies of risk factors are needed. Geographic variation in ASD occurrence has been observed, and urban residence has been suggested to serve as a proxy for etiologic and identification factors in ASD. We examined the association between urbanicity level and ASD at birth and during childhood. The study used a Danish register-based cohort of more than 800,000 children of which nearly 4,000 children were diagnosed with ASD. We found a dose-response association with greater level of urbanicity and risk of ASD. This association was found for residence at birth as well as residence during childhood. Further, we found an increased risk of ASD in children who moved to a higher level of urbanicity after birth. Also, earlier age of ASD diagnosis in urban areas was observed. While we could not directly examine the specific reasons behind these associations, our results demonstrating particularly strong associations between ASD diagnosis and post-birth migration suggest the influence of identification-related factors such as access to services might have a substantive role on the ASD differentials we observed.
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5. Reszka SS, Boyd BA, McBee M, Hume KA, Odom SL. {{Brief Report: Concurrent Validity of Autism Symptom Severity Measures}}. {J Autism Dev Disord};2013 (Jun 27)
The autism spectrum disorder (ASD) diagnostic classifications, according to the DSM-5, include a severity rating. Several screening and/or diagnostic measures, such as the autism diagnostic and observation schedule (ADOS), Childhood Autism Rating Scale (CARS) and social responsiveness scale (SRS) (teacher and parent versions), include an assessment of symptom severity. The purpose of this study was to examine whether symptom severity and/or diagnostic status of preschool-aged children with ASD (N = 201) were similarly categorized on these measures. For half of the sample, children were similarly classified across the four measures, and scores on most measures were correlated, with the exception of the ADOS and SRS-P. While the ADOS, CARS, and SRS are reliable and valid measures, there is some disagreement between measures with regard to child classification and the categorization of autism symptom severity.
