Methylphenidate effects on search strategy of an animal model of attention-deficit/ hyperactivity disorder

This study is aimed at investigating the effects of methylphenidate about search strategy use on the spontaneously hypertensive rat, an animal model of attention-deficit/hyperactivity disorder in the Morris water maze. The methylphenidate group rats were given intraperitoneal injection of methylphenidate (10 mg/kg) dissolved in saline 30 min before daily training for 6 consecutive days. In the same way, the model group and the control group rats were only administered equalized volume of saline, respectively. From the second day of trials, the frequency of using tendency-straight strategy to search the hidden platform was significantly increased in all of the training rats. Additionally, the methylphenidate group rats used straight strategy more frequently than the model group rats did on days 1, 3 and 6, respectively. The data indicated that methylphenidate might play a positive role in improving spatial learning ability of the spontaneously hypertensive rat by adding its straight search strategy use in the Morris water maze.