Sex differences in the contribution of nicotine and nonpharmacological stimuli to nicotine self-administration in rats
Sex differences in the contribution of nicotine and nonpharmacological stimuli to nicotine self-administration in rats
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DOI：
10.1007/s00213-005-2152-3
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发表时间：
2005-07-01
影响因子：
3.4
通讯作者：
Perkins, KA
中科院分区：
文献类型：
--
作者：
Chaudhri, N;Caggiula, AR;Perkins, KA
理论基础：尼古丁和非药理线索对吸烟的影响已有性别差异的报道。虽然非药物环境刺激也被证明影响大鼠的尼古丁自我给药，但还没有人试图研究性别差异对尼古丁和非药物刺激对这一行为的影响。目的：本实验研究了在没有或结合非药物刺激的情况下输注药物时，大鼠对尼古丁的可操作性反应的性别差异。方法：最初，雄性和雌性大鼠在一定剂量范围内(0.03，0.06和0.15 mg kg(-1)inf(-1)，游离基)获得单独尼古丁的自我给药。在稳定获得后，尼古丁注射与弱强化的复合视觉刺激相结合。结果：虽然在没有视觉刺激的情况下，剂量对尼古丁的主动水平反应没有总体影响，但雌性大鼠在FR5时间表上对0.06 mg kg(-1)和0.15 mg kg(-1)Inf(-1)的增强水平的反应比雄性大鼠更多。然而，与相同剂量的男性相比，他们对非强化杠杆的反应也有所增加。与尼古丁单独注射相比，注射尼古丁和视觉刺激的反应倍增，分别为0.03和0.06，但不是0.15 mg kg(-1)inf(-1)：这一影响在雌性大鼠中明显更大。结论：这些数据突出了非药物刺激对尼古丁强化行为的显著贡献，在雄性和雌性大鼠的不同剂量范围内。他们还揭示了在没有非药物刺激或结合药物输送的条件下，对尼古丁的可操作性反应的性别差异。
Rationale: Sex differences have been reported for the impact of nicotine and nonpharmacological cues on smoking. While nonpharmacological environmental stimuli have also been shown to influence nicotine self-administration in rats, there have been no attempts to examine the impact of sex differences in the contributions of nicotine and nondrug stimuli to this behavior. Objectives: This experiment investigated sex differences in operant responding for nicotine in rats when drug infusions were delivered either in the absence of, or in combination with, a nonpharmacological stimulus. Methods: Initially, male and female rats acquired self-administration for nicotine alone across a range of doses (0.03, 0.06, and 0.15 mg kg(-1) inf(-1), freebase). After stable acquisition, nicotine infusions were combined with a weakly reinforcing, compound visual stimulus. Results: While there was no overall effect of dose on active lever responding for nicotine in the absence of the visual stimulus, female rats responded more on the reinforced lever than males at 0.06 and 0.15 mg kg(-1) inf(-1) on an FR5 schedule. However, they also showed increased responding on the nonreinforced lever compared to males at the same doses. Combining nicotine infusions with the visual stimulus doubled responding compared to nicotine alone at 0.03 and 0.06, but not at 0.15 mg kg(-1) inf(-1): this effect was significantly greater for female rats. Conclusions: These data highlight the prominent contribution of nonpharmacological stimuli to nicotine-reinforced behavior across a range of doses in both male and female rats. They also reveal sex differences in operant responding for nicotine under conditions where a nonpharmacological stimulus is either absent, or combined with drug delivery.