Elliott Brenda M, Faraday Martha M, Phillips Jennifer M, Grunberg Neil E
Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences (USUHS), 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
Pharmacol Biochem Behav. 2004 Jan;77(1):21-8. doi: 10.1016/j.pbb.2003.09.016.
Over 4500 adolescents start smoking every day in the United States. Of these, one-third will die prematurely from smoking-related diseases. The current experiment examined the effects of repeated-acute nicotine administration (saline, 0.1, 0.5, or 1.0 mg/kg daily) on elevated plus maze (EPM) and locomotor behaviors of 160 adolescent and adult male and female Sprague-Dawley rats. Nicotine's effects depended on age and sex of animal. On the EPM, nicotine exerted anxiolytic effects (increased percentage of time in the open arms) in adolescent males, but exerted anxiogenic effects (decreased percentage of time in the open arms) in adolescent females and in adult males and females. For adults, peak locomotor activity occurred at the 0.5-mg/kg dosage, and the 1.0-mg/kg dosage reduced activity below the saline level on Day 1 and below the 0.5-mg/kg level on Days 1, 3, and 5. For adolescents, peak locomotor activity occurred at the 1.0-mg/kg dosage and there were no activity-depressant effects. These findings suggest there are age differences in sensitivity to nicotine that may affect vulnerability to long-term tobacco use.
在美国，每天有超过4500名青少年开始吸烟。其中，三分之一的人将因吸烟相关疾病而过早死亡。当前的实验研究了重复急性给予尼古丁（生理盐水、每日0.1、0.5或1.0毫克/千克）对160只青春期和成年雄性及雌性斯普拉格-道利大鼠在高架十字迷宫（EPM）和运动行为方面的影响。尼古丁的作用取决于动物的年龄和性别。在EPM实验中，尼古丁对青春期雄性大鼠有抗焦虑作用（增加在开放臂中的停留时间百分比），但对青春期雌性大鼠以及成年雄性和雌性大鼠有促焦虑作用（减少在开放臂中的停留时间百分比）。对于成年大鼠，运动活性峰值出现在0.5毫克/千克剂量时，而1.0毫克/千克剂量在第1天将活性降低至生理盐水水平以下，在第1、3和5天降低至0.5毫克/千克水平以下。对于青少年大鼠，运动活性峰值出现在1.0毫克/千克剂量时，且没有活性抑制作用。这些发现表明，对尼古丁的敏感性存在年龄差异，这可能会影响长期使用烟草的易感性。
