Radial arm maze (experiments 1 and 2)

One day before and during RAM, rats were food restricted to support reward seeking. Rat chow (Harlan; 1–2 bricks (5 g)) was delivered to home cages after sessions to maintain body weights at 15 % from pre-RAM weights. The RAM, described in detail in (Berg et al. 2015), had eight 10 × 60-cm runways extending radially from a central arena (50-cm diameter). For each session, a receptacle at the end of all 8 arms was pre-loaded with 1/2 of a Kellogg’s Froot Loop®. After starting from the central arena, rats explored the maze until either all arms were entered (four paws in) or 300-s elapsed. The investigator, blind to group, recorded three dependent measures: (1) entries to repeat (ETR), number of arms entered without a repeat (measure of working memory); (2) session time, total time to enter all arms (measure of performance efficiency); and (3) total number of Froot Loops (FL) consumed (measure of appetitive motivation). FL ranged from 0 to 8, never exceeded arms entered, but could be greater or less than ETR.