Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton, NY 13902, USA.
Pharmacol Biochem Behav. 2010 Apr;95(2):242-8. doi: 10.1016/j.pbb.2010.01.013. Epub 2010 Feb 4.
Adolescent rats have been observed to be less sensitive than adults to a number of ethanol effects that may serve as feedback cues to reduce further ethanol intake. Among these findings are a few reports of attenuated sensitivities of adolescents to ethanol-induced motor impairment. The purpose of the present study was to further explore potential age-related differences in ethanol-induced motor impairment in both male and female adolescent (postnatal day [P]28-32), and adult (P68-72) Sprague-Dawley rats using an inclined plane assessment of the negative geotaxis reflex. Adult males displayed significant motor impairment at 1.5 g/kg, whereas adolescent males required higher doses, showing significant motor impairment only at doses of 2.25 g/kg ethanol or greater. Intoxicated practice did not significantly influence level of motor impairment at either age. When female rats of both ages were separately analyzed in terms of their response to ethanol, a dose of 1.5 g/kg ethanol was found to significantly impair adults, whereas adolescent females showed significant motor impairment when challenged with 2.25 g/kg but not 1.5 g/kg ethanol. Yet when the 1.5 g/kg data of females at the two ages were directly compared, no significant age difference was seen at this dose. These data document an attenuated sensitivity of adolescent relative to adult rats to the motor impairing effects of ethanol using a stationary inclined plane test, an effect particularly robust in male animals, and demonstrates the utility of this test for assessment of motor coordination in adolescent and adult rats.
研究人员曾观察到，与成年人相比，青春期大鼠对许多乙醇作用的敏感性较低，这些作用可能作为反馈线索，减少进一步摄入乙醇。这些发现中包括一些关于青春期大鼠对乙醇引起的运动障碍敏感性降低的报告。本研究的目的是进一步探讨雄性和雌性青春期（出生后第 28-32 天）和成年（第 68-72 天）Sprague-Dawley 大鼠中，乙醇诱导的运动障碍的潜在年龄相关差异，方法是使用倾斜平面评估负趋地性反射。成年雄性大鼠在 1.5 g/kg 时表现出明显的运动障碍，而青春期雄性大鼠需要更高的剂量，仅在 2.25 g/kg 或更高剂量的乙醇下才表现出明显的运动障碍。醉酒练习并未显著影响两个年龄段的运动障碍水平。当分别分析两个年龄段的雌性大鼠对乙醇的反应时，发现 1.5 g/kg 乙醇剂量显著损害成年大鼠，而青春期雌性大鼠在 2.25 g/kg 但不是 1.5 g/kg 乙醇挑战下表现出明显的运动障碍。然而，当将两个年龄段的雌性大鼠的 1.5 g/kg 数据直接进行比较时，在该剂量下没有观察到显著的年龄差异。这些数据使用固定倾斜平面测试记录了与成年大鼠相比，青春期大鼠对乙醇致运动障碍作用的敏感性降低，这一效应在雄性动物中尤为明显，并且证明了该测试在评估青春期和成年大鼠运动协调能力方面的实用性。
