Fig. 8.

CCK-8 increases grooming behavior and decreases locomotor activity. Rats were injected ip with CCK-8 (1.8 nmol/kg) or vehicle (saline containing 0.1% BSA) and placed back in their home cage with paper under the cage divided into six equal squares with free access to food and water. Food intake was assessed for 40 min (A). At 10 min after injection, behaviors, including eating (including food approach, B), drinking (including water approach, C), and grooming behavior (washing, licking, and scratching; D), as well as locomotor activity (total number of squares crossed; E) were monitored manually for 30 min by an observer blinded to the animals' treatment. Each behavior was counted again when lasting >5 s. Bars indicate means ± SE of 6–8 rats/group. *P < 0.05 vs. vehicle.