2.3. Activity‐based anorexia model

The activity‐based anorexia (ABA) model is a well validated, commonly used behavioral paradigm in which access to a running wheel paired with restricted feeding results in severe weight loss and reductions in food intake, in addition to increased wheel running activity (Klenotich & Dulawa, 2012). At the start of all experiments, mice were singly housed in clean cages equipped with a running wheel (catalog # 0297; Columbus Instruments, Columbus, OH). Mice were given 3 days to acclimate to their new environment during which Multi Device Interface Software (Columbus Instruments, Columbus, OH) detected the total number of wheel revolutions every 15 minutes. Data were collected during acclimation for two reasons: first, to confirm proper adjustment to the altered light/dark cycle; and second, to determine whether the mouse exhibits sufficient baseline wheel running activity to warrant moving forward in the experiment. Mice running less than 1500 revolutions a day were considered nonrunners and were not used for ABA. Following the acclimation period, baseline daily bodyweight and food intake values were collected 1 hour prior to lights out for 5 days. Wheel running activity continued to be monitored every 15 minutes. Following baseline data collection, the ABA paradigm or relevant control condition was initiated. Food restricted animals were given access to chow for 2 hours a day, presented at the start of the dark cycle. Males and females were always run separately, and cages and wheels were thoroughly cleaned in between cohort runs. Control conditions included mice in cages where running wheels were provided but locked in place to create a food restricted without wheel running condition (FR only) and ad libitum fed animals provided access to a running wheel (WHL only).