0076 Effect of a Tryptophan Enriched Diet on Mood, Cognition, Sleep and Their Associated Neurotransmitters/Hormones in a Mouse Model of Down Syndrome

Abstract Introduction Down’s Syndrome (DS), caused by triplication of genes on human chromosome 21, occurs in ~1 in 800-1000 live births. Individuals with DS display cognitive disabilities, mood and sleep impairment but also a chronic deficit in Tryptophan (TRP). TRP is the precursor of melatonin, involved in circadian control of sleep, and serotonin, involved in mood and cognitive functions. TRP enriched diet (TRPeD) has been shown to improve mood, sleep and cognition in other psychopathologies like Alzheimer disease or depression, that share common features with DS. However, no study has focused on the potential beneficial effect of TRPeD in the context of DS. Methods We conducted the first study testing the hypothesis that TRPeD will improve mood, cognition and enhance sleep, in a mouse model of DS, and that these improvements will be reflected in the level of associated neurotransmitters/hormones. To do so, we tested mood, cognitive abilities, and we monitored the sleep, of mouse model of DS, and their control, before and after 4 weeks under control or TRPeD. Results We showed that a TRPeD improves long term and short-term memory, mood, but not social behavior. TRPeD also decreased the proportion of DS mice taking risky decisions in a decision-making task. The TRPeD also improved the sleep quality and quantity of a mouse model of DS. Conclusion Our study is the first one showing that dietary supplements improve cognition and sleep in a mouse model of DS. In the future, we aim at measuring the level of TRP, serotonin and melatonin in the brain and the blood of our animal to correlate the cognitive and/or sleep improvement with the molecular level of the associated neurotransmitters/hormones. Support (if any)