Department of Psychiatry, University of Florida, Gainesville, FL, USA.
Department of Psychiatry, University of Florida, Gainesville, FL, USA; Department of Neuroscience, University of Florida, Gainesville, FL, USA.
Pharmacol Biochem Behav. 2021 Aug;207:173224. doi: 10.1016/j.pbb.2021.173224. Epub 2021 Jun 28.
Very few people are able to quit smoking, and therefore it is essential to know which factors contribute to the development of compulsive nicotine use. These studies aimed to investigate if early-adolescent nicotine exposure causes locomotor sensitization and affects anxiety-like behavior and the spontaneous acquisition of intravenous nicotine self-administration. Early-adolescent male and female rats were treated with nicotine from postnatal (P) days 24 to 42, and anxiety-like behavior and locomotor activity were investigated one day after the cessation of nicotine treatment and in adulthood (>P75). The spontaneous acquisition of nicotine self-administration was also investigated in adulthood. The rats self-administered 0.03 mg/kg/infusion of nicotine for six days under a fixed-ratio (FR) 1 schedule and four days under an FR2 schedule (3-h sessions). Repeated nicotine administration increased locomotor activity, rearing, and stereotypies in a small open field in adolescent male and female rats. One day after the last nicotine injection, the percentage of open arm entries in the elevated plus-maze test was decreased in the males and increased in the females. However, locomotor activity in the small open field was unaffected. Adolescent nicotine treatment did not affect anxiety-like behavior and locomotor activity in adulthood. During the 10-day nicotine self-administration period, the females had a higher level of nicotine intake than the males. Adolescent nicotine treatment decreased nicotine intake in the females. In conclusion, these findings indicate that repeated nicotine administration during adolescence causes robust behavioral sensitization and leads to lower nicotine intake in females throughout the acquisition period in adulthood in rats.
很少有人能够戒烟，因此了解哪些因素导致强迫性尼古丁使用是至关重要的。这些研究旨在调查青春期前接触尼古丁是否会导致运动敏化，并影响焦虑样行为和静脉内尼古丁自我给药的自发获得。雄性和雌性幼鼠从出生后（P）第 24 天到第 42 天接受尼古丁处理，在停止尼古丁处理后一天和成年期（>P75）调查焦虑样行为和运动活动。还在成年期调查了静脉内尼古丁自我给药的自发获得。大鼠在固定比率（FR）1 方案下自我给予 0.03mg/kg/ 次的尼古丁，在 FR2 方案（3 小时会议）下自我给予 4 次。重复尼古丁给药会增加青春期雄性和雌性大鼠在小旷场中的运动活动、竖起和刻板行为。在最后一次尼古丁注射后一天，高架十字迷宫测试中开放臂进入的百分比在雄性中减少，而在雌性中增加。然而，小旷场中的运动活动不受影响。青春期尼古丁处理不会影响成年期的焦虑样行为和运动活动。在 10 天的尼古丁自我给药期间，雌性的尼古丁摄入量高于雄性。青春期尼古丁处理减少了雌性的尼古丁摄入量。总之，这些发现表明，青春期重复给予尼古丁会导致强烈的行为敏化，并导致成年期在获得期间雌性的尼古丁摄入量降低。
