Irvine E E, Bagnalasta M, Marcon C, Motta C, Tessari M, File S E, Chiamulera C
Psychopharmacology Research Unit, Centre for Neuroscience, GKT School of Biomedical Sciences, King's College London, UK.
Psychopharmacology (Berl). 2001 Jan;153(3):315-20. doi: 10.1007/s002130000586.
Most smokers report smoking has an anxiolytic effect, which may contribute to nicotine dependence.
To examine effects in the social interaction test (SI) of anxiety after 4 weeks' self-administered nicotine (15 infusions of 0.03 mg/kg, totalling 0.45 mg/kg per day), and after 24 and 72 h of withdrawal. The effect of exposure to the operant chamber on withdrawal responses was also examined.
Animals were trained to self-administer saline or nicotine and after 4 weeks they were tested in SI after their daily self-administration session. Animals were retested after 24 and 72 h withdrawal, when they were either taken directly from the home cage or were tested 5 min after a 30-min exposure to the operant chamber.
Compared with the saline control group, the animals that had been self-administering nicotine for 4 weeks showed decreased social interaction with no decrease in locomotor activity, indicating a significant anxiogenic effect of the nicotine infusions. There was no change in social interaction after 24 and 72 h withdrawal from chronic nicotine, regardless of whether or not the rats were exposed to the operant chamber just prior to being tested.
Nicotine self-administration is not maintained because of its anxiolytic effect, but despite, or because of, its anxiogenic effect. There was no evidence of an anxiogenic response after either 24 or 72 h of withdrawal and thus increased anxiety on withdrawal from nicotine does not seem to contribute to nicotine self-administration.
大多数吸烟者称吸烟具有抗焦虑作用，这可能导致尼古丁依赖。
研究在社交互动测试（SI）中，自我给药尼古丁4周（每天15次注射，每次0.03mg/kg，总计0.45mg/kg）后以及戒断24小时和72小时后的焦虑影响。还研究了暴露于操作箱对戒断反应的影响。
训练动物自我给药生理盐水或尼古丁，4周后在每日自我给药后进行SI测试。在戒断24小时和72小时后重新测试动物，此时它们要么直接从饲养笼中取出，要么在暴露于操作箱30分钟后5分钟进行测试。
与生理盐水对照组相比，自我给药尼古丁4周的动物社交互动减少，但运动活动未减少，表明尼古丁注射具有显著的致焦虑作用。从慢性尼古丁戒断24小时和72小时后，无论大鼠在测试前是否暴露于操作箱，社交互动均无变化。
尼古丁自我给药并非因其抗焦虑作用而维持，而是尽管有或因其致焦虑作用而维持。在戒断24小时或72小时后均无致焦虑反应的证据，因此尼古丁戒断时焦虑增加似乎并非尼古丁自我给药的原因。
