Article Figures & Data
Figures
- Figure 1.
Experimental apparatus and design of the sequential food-water navigation task with variable delayed rewards. A, Open field, reward cylinders (food site, water site) and tone cylinder (tone site) for the task. Windows for nose pokes (reward locations) are indicated. The tone cylinder also contained a small window at the same position as the reward cylinders. B, Schematic of the movements required for the rats to receive rewards at both sites. The rats performed the task under two reward conditions. In the SDR condition, the rats obtained a reward after 2 s of nose poking at each reward site. In the LDR condition, the rats were required to poke their nose for 7–11 s before obtaining the reward. Each reward condition lasted for 30 min and was preceded by a rest period. C, Locations of the microdialysis probes in the DRN. Black bars represent the 2 mm length of the dialysis membranes. Numbers beside each plate correspond to millimeters from bregma. Coronal drawing modified from Paxinos and Watson (1998) with permission.
- Figure 2.
Changes in serotonin efflux in the mPFC during a task sequence. A, A typical example of serotonin efflux in the mPFC during the task sequence. B, Average serotonin levels in the mPFC during all reward conditions (n = 3; ±SEM). Asterisks indicate significant differences, as assessed by a paired t test, *p < 0.05, **p < 0.01.
- Figure 3.
Effect of inhibition of serotonergic neural activity on the sequential food-water navigation task with variable delayed rewards. A–C, Markers represent the means of total trials (A), choice errors (B), and wait errors (C) every 10 min during all reward conditions. Error bars represent ±SEM (n = 10). Straight line, Food-related trial; dotted line, water-related trial. Gray color indicates the number of each trial in the serotonin inhibition condition.
- Figure 4.
Number of behavioral events during the different reward and drug conditions. Behavioral events during normal (N), inhibition (I), and recovery (R) conditions are shown. A–C, Markers represent the means of the total trials (A), choice errors (B). and wait errors (C) during a 30 min period in the LDR condition. D–F, Markers represent the means of the total trials (D), choice errors (E), and wait errors (F) during a 30 min period in the SDR condition. Error bars represent ±SEM (n = 10). Asterisks indicate significant differences assessed by a paired t test, *p < 0.05, **p < 0.01. White bar, Food-related trial; gray bar, water-related trial.
- Figure 5.
Number of reward choice errors classified by previous trials. Reward choice errors during normal (N), inhibition (I), and recovery (R) conditions are shown. A, Markers represent the means of the food choice errors and water choice errors preceded by water success (left) and food success (right). B, Markers represent the means of the food choice errors and water choice errors that occurred after food wait errors (left) and water wait errors (right). Error bars represent ±SEM. White bar, Food-related trial; gray bar, water-related trial.
