Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders

Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively

Assessing the Relationship between Dental Caries and Anthropometric Indices in 9-11-Year-old Primary School Children of Shiraz

Abstract Background and aim: Dental caries is the most prevalent chronic childhood disease that has a profound impact on the health of both the individual and community health. On the other, the overweight and underweight in children is a major public health concern influenced by common factors with dental caries. The aim of the present study was to assess the relationship between DMFT (Decay-Missing-Filled-permanent teeth) and anthropometry indices in 9-11 year old primary school children of the city of Shiraz, Iran-2012. Methods: The present cross-sectional study was conducted on primary school children, aged 9 to 11 years, selected by cluster random sampling in four areas of Shiraz city, in 2012. The prevalence of children with dental caries was calculated by measuring the number of teeth decayed, missing or filled duo to caries (DMFT) indices using the WHO screening standards. Weight, height, and sitting height were measured and body mass index (BMI) and leg height were calculated. The association between Anthropometry and DMFT were examined using bivariate correlation and linear regression tests by the SPSS software. The difference mean DMFT index between five groups of BMI was evaluated by ANOVA and post hoc Tukey tests. Results: A total of 974 pupils were studied. Mean DMFT was 0.94±1.46. There were significant association between DMFT and BMI (r=-0/91 p=0/005). Mean DMFT was significantly reduced from underweight children to obese children (p=0/027). Conclusion: Underweight children have a higher risk of developing caries in their permanent teeth. Key words: Body Mass Index, Anthropometry, DMF Inde