Design of experiments to determine the effects of intermittent fasting (IF) on cognitive function and hippocampal neuroinflammation. (A) For the biochemical experiments, rats were subjected to IF or ad libitum Control diets for 30 days. To determine whether IF modulated the inflammatory response to a subsequent challenge, rats were injected intravenously with either 1 mg/kg lipopolysaccharide (LPS) or saline on day 31, and 2 hours later brain tissue and serum samples were collected for subsequent analysis. (B) For the behavioral experiments, rats were subjected to the habituation session of the Barnes maze and were immediately injected intravenously with either 1 mg/kg LPS or saline on day 31. Barnes maze testing sessions and inhibitory avoidance tests were performed on days 32 to 36 and 37 to 38, respectively. Locomotor activity test was performed 24 hours after LPS administration and rotarod tests were performed on days 32 to 35.