1. Belger A, Carpenter KL, Yucel GH, Cleary KM, Donkers FC. {{The Neural Circuitry of Autism}}. {Neurotox Res}. 2011 Jan 7.
Autism is a complex neurodevelopmental disorder, characterized by deficits in social emotional, and language domains, as well as repetitive restrictive behaviors. The vast heterogeneity of the clinical and behavioral symptoms has made it rather difficult to delineate the neural circuitry affiliated with these domains of dysfunction. The current review aims at broadly outlining the latest research into the neurobiology and neural circuitry underlying the core domains of deficits in autism. We further discuss new avenues of research that can further our understanding of the dimensions of this complex disorder.
2. Evers K, Noens I, Steyaert J, Wagemans J. {{Embodied simulation and the meaning of facial expression in autism}}. {Behav Brain Sci}. 2010 Dec;33(6):445-6.
We outline three possible shortcomings of the SIMS model and specify these by applying the model to autism. First, the SIMS model assigns a causal role to brain processes, thereby excluding individual and situational factors. Second, there is no room for subjective and high-level conceptual processes in the model. Third, disentangling the different stages in the model is very difficult.
3. Rajaei S, Erlandson A, Kyllerman M, Albage M, Lundstrom I, Karrstedt EL, et al. {{Early infantile onset »congenital » rett syndrome variants: Swedish experience through four decades and mutation analysis}}. {J Child Neurol}. 2011 Jan;26(1):65-71.
The early infantile onset »congenital » variant of Rett syndrome presents with deviations of behavior from very early infancy. Here, we report on a clinical-genetic study in a collected series of 14 Swedish girls with early infantile onset Rett syndrome phenotype. The clinical diagnosis was based on symptom onset before the age of 6 months and the patients fulfilled 3 or more Rett variant criteria and 5 or more supportive criteria. Genotype-phenotype correlation studies in the CDKL5-gene have recently shown clinical associations to early infantile onset Rett variants. Mutation analyses for both the MECP2-gene and the CDKL5-gene were, therefore, performed. Of interest, we found a large deletion covering 2 exons in MECP2, which underlines the importance of MECP2 mutation screening even for the »atypical » early infantile onset variants of Rett syndrome. No early infantile onset Rett syndrome patients in this study had the previously well-known hotspot mutations in the MECP2-gene.
4. Ricciardi S, Boggio EM, Grosso S, Lonetti G, Forlani G, Stefanelli G, et al. {{Reduced AKT/mTOR signaling and protein synthesis dysregulation in a Rett syndrome animal model}}. {Hum Mol Genet}. 2011 Jan 6.
Rett syndrome (RTT) is a neurodevelopmental disorder with no efficient treatment that is caused in the majority of cases by mutations in the gene MECP2. RTT becomes manifest after a period of apparently normal development and causes growth deceleration, severe psychomotor impairment and mental retardation. Effective animal models for RTT are available and show morphofunctional abnormalities of synaptic connectivity. However, the molecular consequences of MeCP2 disruption leading to neuronal and synaptic alterations are not known. Protein synthesis regulation via the mammalian target of rapamycin (mTOR) pathway is crucial for synaptic organization and its disruption is involved in a number of neurodevelopmental diseases. We investigated the phosphorylation of the ribosomal protein (rp) S6, whose activation is highly dependent from mTOR activity. Immunohistochemistry showed that rpS6 phosphorylation is severely affected in neurons across cortical areas of Mecp2 mutants and that this alteration precedes the severe symptomatic phase of the disease. Moreover, we found a severe defect of initiation of protein synthesis in the brain of presymptomatic Mecp2 mutant that was not restricted to specific subset of transcripts. Finally, we provide evidence for a general dysfunction of the Akt/mTOR, but not ERK, signaling associated with the disease progression in mutant brains. Our results indicate that defects in Akt/mTOR pathway are responsible for the altered translational control in Mecp2 mutant neurons and disclosed a novel putative biomarker of the pathological process. Importantly, this study provides a novel context of therapeutic interventions that can be designed to successfully restrain or ameliorate the development of RTT.
5. Winkielman P. {{Embodied and disembodied processing of emotional expressions: Insights from autism spectrum disorders}}. {Behav Brain Sci}. 2010 Dec;33(6):463-4.
Processing of facial expressions goes beyond simple pattern recognition. To elucidate this problem, Niedenthal et al. offer a model that identifies multiple embodied and disembodied routes for expression processing, and spell out conditions triggering use of different routes. I elaborate on this model by discussing recent research on emotional recognition in individuals with autism, who can use multiple routes of emotion processing, and consequently can show atypical and typical patterns of embodied simulation and mimicry.
6. Ye H, Liu J, Wu JY. {{Cell Adhesion Molecules and Their Involvement in Autism Spectrum Disorder}}. {Neurosignals}. 2011 Jan 6;18(2):62-71.
Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by abnormalities in social interaction, language development and behavior. Recent genetic studies demonstrate that alterations in synaptic genes including those encoding cell adhesion molecules and their interaction partners play important roles in the pathogenesis of ASD. Systematic analyses of different cell adhesion molecule genes will help elucidate their normal functions and regulatory mechanisms in the establishment and maintenance of normal neural circuits and uncover genetic aberrations contributing to ASD.
