6533b862fe1ef96bd12c68fd

RESEARCH PRODUCT

impact of dietary intake of n-3 polyunsaturated fatty acids on the physiology of the peripheral olfactory system in young mice

subject

description

Abstract : Olfaction plays a major role in the detection of volatile chemical signals present in the environment and triggers behaviors such as food intake, social interactions or danger avoidance. Recent studies suggested that nutritional and metabolic status of individuals may influence their olfactory capacities. Olfactory disorders have been observed in people with pathologies such as obesity and diabetes as well as in rodents exposed to obesogenic or diabetogenic diets. The physiological mechanisms underlying these dysfunctions are not known. One hypothesis is that a nutritional imbalance in lipids might alter the functioning of the peripheral olfactory system. In this context, the objective of this thesis was to characterize the impact of diets unbalanced in n-3 polyunsaturated fatty acid (PUFAs) on the physiology of the peripheral olfactory system in miceTo this end, female mice were fed ad libitum diets either deficient (LOW diet) or supplemented (HIGH diet) in n-3 PUFA during the perinatal period. Male offspring were then fed with the same experimental diets until 8 weeks of age. Olfactory behavior tests were performed in the young mice at the age of 3 and 8 weeks. The fatty acid composition of olfactory mucosa, as well as the expression of genes involved in different cellular pathways, were analyzed. The electrophysiological responses to odorants were also measured in the olfactory mucosa.Our data showed that the LOW and HIGH diets significantly modified the fatty acid profiles of the olfactory mucosa of the offspring as soon as 3 weeks old. These diets also delayed olfactory sensory neurons (OSN) maturation but did not affect neurogenesis. In addition, the n-3 PUFA-deficient diet impaired the olfactory information processing at the peripheral level by reducing the expression of some actors involved in the olfactory signal transduction cascade. However, the olfactory abilities of young mice were not altered.In conclusion, our work showed that olfactory abilities of mice fed diets unbalanced in n-3 PUFA from the perinatal period to adulthood were maintained despite molecular and functional changes at the peripheral level. These observations support the idea that the olfactory system exhibits adaptive faculties to ensure a sense of smell continuity