Data for: Age and an obesogenic diet affect mouse behaviour in a sex-dependent manner

Obesity is rising globally and is associated with neurodevelopmental and psychiatric disorders among children, adolescents, and young adults. Whether obesity is the cause or the consequence of these disorders remains unclear. To examine the behavioural effects of obesity systematically, locomotion, anxiety, and social behaviour were assessed in male and female C57Bl/6J mice using the open field, elevated plus maze and social preference task. First, the effects of age and sex were examined in control mice, before investigating post-weaning consumption of a high fat, high sugar diet commonly consumed in human populations with high rates of obesity. In the open field and elevated plus maze, locomotor activity and anxiety-related behaviours reduced with aging in both sexes, but with different sex-specific profiles. The high fat, high sugar diet reduced food and calorie intake and increased body mass and fat deposition in both sexes. In the open field, both male and female mice on the obesogenic diet showed reduced locomotion, whereas, in the elevated plus maze, only females on the obesogenic diet displayed reduced anxiety-related behaviours. Both male and female mice on the obesogenic diet had a significantly higher social preference index than controls. In conclusion, the findings demonstrate that the behavioural effects of age and of diet-induced obesity all depend on the sex of the mouse. This emphasises the importance of considering the age of the animal and including both sexes when assessing behavioural phenotypes arising from dietary manipulations.Funding provided by: Medical Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000265Award Number: MR/N013433/1Behavioural data from the open field, elevated plus maze and social preference tasks was collected using a ceiling mounted webcam over the testing apparatus followed by manual experimenter counting, blind to cohort where possible. Food, calorie and protein intake for a cage of mice was determined by measuring food weekly over a 24 hour period and expressed as intake per day per gram of the total weight of mice in each cage. Body weight of individual mice was monitored weekly from weaning to the end of the experimental period. A subset of the females and males in the two diet groups were used to quantify total body fat and lean mass by Dual Energy X-ray Absorptiometry (DEXA) scanning (Lunar PIXImus densitometer; GE Healthcare) and/or to measure the weights of the individual fat deposits and body organs. All data sets were added to an Excel spreadsheet and statistical comparisons between groups were made using GraphPad Prism (version 9)