使用颅内自我刺激测量尼古丁对青少年和成年雄性和雌性大鼠的奖赏效应。
Rewarding Effects of Nicotine in Adolescent and Adult Male and Female Rats as Measured Using Intracranial Self-stimulation.
机构信息
Department of Psychiatry, University of Florida, Gainesville, FL.
Department of Histology and Embryology, University of South China, Hengyang, Hunan, China.
出版信息
Nicotine Tob Res. 2020 Feb 6;22(2):172-179. doi: 10.1093/ntr/nty249.
INTRODUCTION
Tobacco is highly addictive, and after the development of dependence, it is difficult to quit smoking. Therefore, it is important to understand the factors that play a role in the initiation of smoking. The rewarding effects of nicotine play a role in the initiation of smoking and the goal of the present study was to determine the rewarding effects of nicotine in adolescent and adult male and female rats.
METHODS
Male and female Wistar rats were prepared with intracranial self-stimulation (ICSS) electrodes between postnatal day (P) 23 and 33. They were then trained on the ICSS procedure and the effect of nicotine (0, 0.03, 0.1, 0.3 mg/kg) on the reward thresholds and response latencies was investigated during adolescence (P40-59) or adulthood (>P75).
RESULTS
Nicotine lowered the brain reward thresholds of the adult and adolescent male and female rats. The nicotine-induced decrease in the reward thresholds was the same in the adult male and adult female rats. However, nicotine induced a greater decrease in the reward thresholds of the adolescent female rats than the adolescent male rats. Nicotine decreased the response latencies of all groups and there was no effect of age or sex.
CONCLUSIONS
Nicotine enhances reward function and psychomotor performance in adolescent and adult male and female rats. Adolescent female rats are more sensitive to the acute rewarding effects of nicotine than adolescent male rats. Therefore, the rewarding effects of nicotine might play a greater role in the initiation of smoking in adolescent females than in adolescent males.
IMPLICATIONS
The great majority of people start smoking during adolescence. The present studies suggest that during this period female rats are more sensitive to the acute rewarding effects of low and intermediate doses of nicotine than male rats. The rewarding properties of nicotine play a role in the initiation of smoking and establishing habitual smoking. Therefore, the present findings might explain why adolescent females are at a higher risk for becoming nicotine dependent than adolescent males.
简介
烟草具有很强的成瘾性，在产生依赖后，很难戒烟。因此，了解导致吸烟的因素非常重要。尼古丁的奖赏效应在吸烟的开始阶段起着作用，本研究的目的是确定尼古丁对青少年和成年雄性和雌性大鼠的奖赏效应。
方法
雄性和雌性 Wistar 大鼠在出生后第 23 天至 33 天之间植入颅内自我刺激（ICSS）电极。然后，对它们进行 ICSS 程序训练，并在青春期（P40-59）或成年期（>P75）时研究尼古丁（0、0.03、0.1、0.3 mg/kg）对奖赏阈值和反应潜伏期的影响。
结果
尼古丁降低了成年和青春期雄性和雌性大鼠的大脑奖赏阈值。成年雄性和成年雌性大鼠的奖赏阈值降低情况相同。然而，尼古丁在青春期雌性大鼠中引起的奖赏阈值降低幅度大于青春期雄性大鼠。尼古丁降低了所有组的反应潜伏期，且年龄和性别均无影响。
结论
尼古丁增强了青春期和成年雄性和雌性大鼠的奖赏功能和运动表现。青春期雌性大鼠比青春期雄性大鼠对尼古丁的急性奖赏效应更为敏感。因此，与青春期男性相比，尼古丁的奖赏效应可能在青春期女性开始吸烟中起更大的作用。
意义
绝大多数人在青春期开始吸烟。本研究表明，在这个时期，雌性大鼠比雄性大鼠对低剂量和中剂量尼古丁的急性奖赏效应更为敏感。尼古丁的奖赏特性在吸烟的开始阶段和习惯性吸烟的建立中起着作用。因此，目前的发现可以解释为什么青春期女性比青春期男性更容易对尼古丁产生依赖。
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