1. Croen LA, Goines P, Braunschweig D, Yolken R, Yoshida CK, Grether JK, Fireman B, Kharrazi M, Hansen R, Van de Water J. {{Brain-derived neurotrophic factor and autism: maternal and infant peripheral blood levels in the Early Markers for Autism (EMA) Study}}. {Autism Res};2008 (Apr);1(2):130-137.
The diagnosis of autism is based solely on behavioral characteristics. There is currently no laboratory test that can be done to identify autism. In this study, we investigated a molecule called brain derived neurotrophic factor (BDNF) as a possible early biologic marker for autism. BDNF is a small protein found throughout the central nervous system and in circulating blood. We measured the level of BDNF in blood collected from women during pregnancy and from their babies at birth. We found that the concentration of BDNF in the maternal mid-pregnancy and newborn blood specimens was similar for children with autism, children with mental retardation, and children with typical development. The results of this study suggest that BDNF is unlikely to be a useful early biologic marker for autism. SCIENTIFIC ABSTRACT: OBJECTIVE: To investigate levels of brain-derived neurotrophic factor (BDNF) in mid-pregnancy and neonatal blood specimens as early biologic markers for autism. METHODS: We conducted a population-based case-control study nested within the cohort of infants born from July 2000 – September 2001 to women who participated in the prenatal screening program in Orange County, California. Cases (n=84) were all children receiving services for autism at the Regional Center of Orange County. Two comparison groups from the same study population were included: children with mental retardation or developmental delay (n=49) receiving services at the same regional center, and children not receiving services for developmental disabilities, randomly sampled from the California birth certificate files (n=159), and frequency-matched to autism cases on sex, birth year, and birth month. BDNF concentrations were measured in archived mid-pregnancy and neonatal blood specimens drawn during routine prenatal and newborn screening using a highly sensitive bead-based assay (Luminex). RESULTS: The concentration of BDNF in maternal mid-pregnancy and neonatal specimens was similar across all three study groups. CONCLUSION: These data do not support previous findings of an association between BDNF and autism and suggest that the concentration of BDNF during critical periods of early neurodevelopment is not likely to be a useful biomarker for autism susceptibility.
2. Nag N, Moriuchi JM, Peitzman CG, Ward BC, Kolodny NH, {{Berger-Sweeney JE. Environmental enrichment alters locomotor behaviour and ventricular volume in Mecp2 1lox mice}}. {Behav Brain Res};2009 (Jan 3);196(1):44-48.
Rett syndrome (RTT) is an autistic spectrum developmental disorder associated with mutations in the X-linked Mecp2 gene, and severe behavioural and neuropathological deficits. In a mouse model of RTT (Mecp2(1lox)), we examined whether environmental enrichment (EE) alters behavioural performance and regional brain volume. At weaning, Mecp2(1lox) and control mice were assigned to enriched or standard housing. From postnatal day 29 to 43, mice were subjected to behavioural tasks measuring motor and cognitive performance. At postnatal day 44, volumes of whole brain, cerebellum, ventricles, and motor cortex were measured using magnetic resonance imaging. EE provided subtle improvements to locomotor activity and contextual fear conditioning in Mecp2(1lox) mice. Additionally, EE reduced ventricular volumes, which correlated with improved locomotor activity, suggesting that neuroanatomical changes contribute to improved behaviour. Our results suggest that post-weaning EE may provide a non-invasive palliative treatment for RTT.
