Fang T Y, Tan S E
Graduate Institute of Behavioral Science, Kaohsiung Medical College, Taiwan, ROC.
Chin J Physiol. 1998;41(1):53-8.
Treatment of attention-deficit hyperactivity disorder with stimulants such as methylphenidate reduces motor activity and improves performance of tasks requiring attention, learning, and memory. The present study reports the patterns of behavioral activity of rats of different ages, and the effect of methylphenidate on the behavioral activity. The behavioral activity of Wistar male rats was measured on the nine hole-board apparatus. In experiment I, the behavioral activity of rats from three age groups (4, 8 and 12 weeks old) were measured in terms of the activity time, specific exploratory behavior, diverse exploratory behavior and defecation number. The rats were re-exposed to the hole-board again every two weeks until they 14 weeks old. The younger rats showed higher activity level compared to the older rats. The activity level decreased as the rats grew older. The younger rats also showed more diverse exploratory behavior, but less specific exploratory behavior compared with the older rats. These suggested that the younger rats may be more hyperactive in nature, and less prone to focus on the specific targets. In experiment II, the methylphenidate (4 mg/kg, i.p.) injected rats showed higher activity level than the controls across the three age groups. The exploratory behavioral patterns were not significantly different among the three age groups. This suggests that the methylphenidate injection raises the motor activity level without affecting the exploratory tendency of rats.
使用哌甲酯等兴奋剂治疗注意力缺陷多动障碍可降低运动活动，并改善需要注意力、学习和记忆的任务表现。本研究报告了不同年龄大鼠的行为活动模式，以及哌甲酯对行为活动的影响。在九孔板装置上测量Wistar雄性大鼠的行为活动。在实验I中，从活动时间、特定探究行为、多样探究行为和排便次数方面测量了三个年龄组（4周、8周和12周龄）大鼠的行为活动。每两周将大鼠再次置于孔板上，直至其14周龄。与老年大鼠相比，幼年大鼠表现出更高的活动水平。随着大鼠年龄增长，活动水平下降。与老年大鼠相比，幼年大鼠还表现出更多样的探究行为，但特定探究行为较少。这表明幼年大鼠在本质上可能更多动，且不太容易专注于特定目标。在实验II中，注射哌甲酯（4毫克/千克，腹腔注射）的大鼠在三个年龄组中均表现出比对照组更高的活动水平。三个年龄组之间的探究行为模式没有显著差异。这表明注射哌甲酯可提高运动活动水平，而不影响大鼠的探究倾向。
