Here we investigated mouse models carrying different deletions across the Nrxn1 gene, mimicking three distinct ASD-associated deletions observed in humans, and assessed autism-related mouse behaviors. How NRXN1 deletions, which can occur at various positions across the gene, contribute to behaviors associated with autism remains unknown. Importantly, mice with heterozygous loss of Nrxn1, as found in numerous autistic individuals, show an elevated propensity to manifest autism-related phenotypes, supporting the use of models with this genomic architecture to study ASD etiology and assess additional genetic variants associated with autism.ĭeletions of one of the two copies of the Neurexin1 ( NRXN1) gene are among the most common genetic anomalies in autism spectrum disorder (ASD), a neurodevelopmental condition afflicting 1 in every 44 children in the United States. These findings demonstrate the importance of Nrxn1α gene dosage in regulating social, circadian, and motor functions, and the variables of sex and genomic positioning of CNVs in the expression of autism-related phenotypes. In contrast, mice bearing an intronic deletion of Nrxn1 did not display alterations in any of the behaviors assessed. Heterozygous or homozygous loss of Nrxn1α affected the preference for social novelty in male mice, and notably, enhanced repetitive motor skills and motor coordination in both sexes. ![]() We found that homozygous loss of Nrxn1α resulted in enhanced aggression in males, reduced affiliative social behaviors in females, and significantly altered circadian activities in both sexes. To address the functional contribution of NRXN1 CNVs to behavioral phenotypes relevant to ASD, we carried out systematic behavioral phenotyping of an allelic series of Nrxn1 mouse models: one carrying promoter and exon 1 deletion abolishing Nrxn1α transcription, one carrying exon 9 deletion disrupting Nrxn1α protein translation, and one carrying an intronic deletion with no observable effect on Nrxn1α expression. PTI.Copy number variations (CNVs) in the Neurexin 1 ( NRXN1) gene, which encodes a presynaptic protein involved in neurotransmitter release, are some of the most frequently observed single-gene variants associated with autism spectrum disorder (ASD). "Many devices have tried to use activity to assess sleep structures, but our method is simple, transparent, and works especially in long-term recordings," Roenneberg said. ![]() Those measures showed that movement patterns reflect sleep cycles and replicate the dynamics seen in the lab. The researchers called the new measure "locomotor inactivity during sleep" (LIDS). "It was flabbergasting how it clarified the structures," Roenneberg said. They used a simple conversion to measure inactivity (as opposed to activity) on a scale of near zero to 100, with 100 representing total inactivity. It was hard to discern the cyclical sleep patterns normally seen with other, more complicated devices in the lab.īy focusing on periods of inactivity during the night, a much clearer cyclical pattern began to emerge. However, the patterns of activity during sleep collected using the devices appeared rather messy. In the new study published in the journal Current Biology, the researchers looked at actimeter data collected over more than 20,000 days from 574 subjects, aged 8 to 92 years. The next step was to find a way to collect objective measurements of sleep characteristics on similarly large numbers of people. The team of researchers had been collecting information on sleep duration and quality via questionnaire. "This will help many who have sleep problems and will hopefully increase the appreciation for the importance of sleep for our health and well-being," Till Roenneberg from LMU Munich said. The findings are the latest in a larger, ongoing human sleep project, designed to learn more about sleep and its essential role in our lives by collecting sleep data on thousands of people in the real world. ![]() The researchers from the Ludwig Maximilian University of Munich (LMU) in Germany used the actimeters to assess rest/activity cycles not just over the course of the waking day, but also during sleep itself. The gadget, called actimeter, records data on wrist movement from which one can obtain activity patterns for up to three months. BERLIN: A new wrist-worn gadget may help people with sleep problems by objectively tracking their real-life sleep habits and quality, scientists say.
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