Circulating IGF-1 related exercise associated with improved spatial memory in elderly mice

This study examined the correlation between the circulating and hippocampal IGF-1 levels in elderly mice after exercise intervention and evaluated the relationship between circulating and hippocampal IGF-1 levels in improving the spatial memory function of elderly mice. Methods: Nine-month-old female mice were divided into treadmill, swimming, and control groups, each consisting of ten mice. Exercises were carried out for six weeks, five times a week. Before and after training, Y-maze spontaneous alternation tests were carried out for spatial working memory. After six weeks of exercise, hippocampal and circulating IGF-1 levels were measured with the ELISA method. ANOVA was performed to analyze differences between groups. Pearson’s or Spearman’s correlation analysis was performed to assess the correlation of hippocampal and circulating IGF-1 levels with spatial working memory and the correlation between circulating IGF-1 levels and hippocampal IGF-1 levels. Results: The circulating IGF-1 levels significantly increased (p < 0.05) in the treadmill and swimming groups compared to the control, while the hippocampal IGF-1 levels only significantly increased (p < 0.05) in the swimming group. There was a significant correlation between spatial memory and blood IGF-1 levels (p = 0.002), but no significant correlation (p = 0.122) existed between spatial memory and hippocampal IGF-1 levels. There was a significant correlation between serum IGF-1 levels and hippocampal IGF-1 levels (p = 0.028). Conclusion: Circulating IGF-1 levels were correlated with hippocampal IGF-1 levels. However, hippocampal IGF-1 levels had yet to demonstrate any significant correlation with improved memory function Keywords: IGF-1, exercise, ageing, memory, hippocampus