*2.9. Lickometer-Assessed Preference for Simultaneously Presented GM and CM in Sated Adult Rats*

Six 12-week old male rats were housed individually in cages equipped with bottles attached to lickometers (Lafayette Instruments, Lafayette, IN, USA). The animals were previously given GM and CM to prevent neophobia (the pre-exposure was simultaneous). They were accustomed to receiving a choice between GM and CM on two separate days for 30 min (random order of bottles) in lickometer cages. On the experimental day, standard chow and water were removed from the cages and animals were given simultaneous access to GM and CM (room temperature) for 30 min. The number of licks on each bottle was counted and analyzed (Scurry Activity Monitoring software, Lafayette, IN, USA), both as total number of licks as well as number of licks per 5-minute interval. We also assessed the cluster number (number of bouts of licking—each bout was defined as continuous licking interspaced by no more than 0.5 s between each other) and an average cluster length (bout duration measured in seconds) of GM vs. CM. This feeding experiment was conducted in a separate cohort of animals.
