Figure 5.

Schematic of Delay-Discounting Task. (A) Reward arm (marked in yellow) and two start arms (marked in red) on the elevated T-maze. (B) Sooner smaller choice: the animal waited for 3 s to obtain one sugar pellet. Later larger choice: the animal waited for 10 s and obtained four sugar pellets. Once the animal entered one reward arm, the other reward and start arms were blocked by wooden barriers to confine the animal to the chosen arm for the entire delay period. (C) For each day of testing, three blocks of trials were offered, each associated with a different length of LL delay (10 s, 20 s, or 40 s). The SS delay remained constant (3 s). The blocks were separated by an inter-block interval of 5 min. Drug infusion sequences follow an ABBA pattern. On day 1 and day 4, a certain animal would receive one type of infusion (0.9% saline or muscimol), and day 2 and day 3 of the alternative type of infusion.