Bolin B Levi, Akins Chana K
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA.
Behav Processes. 2012 Oct;91(2):177-83. doi: 10.1016/j.beproc.2012.07.004. Epub 2012 Jul 24.
In the current study, male quail were administered methamphetamine (3.0 or 5.6 mg/kg IP) or saline once daily for 10 days and locomotor activity was assessed. Following a 31-day withdrawal period, sexual conditioning trials were conducted such that a conditioned stimulus (CS) was presented prior to a copulatory opportunity with a female quail. Male quail treated with methamphetamine (5.6 mg/kg) showed a decrease in locomotor activity from Trial 1 to Trial 10 suggesting a potential tolerance effect. Following the 31-day withdrawal period, all male quail that received the CS paired with a copulatory opportunity showed enhanced approach to the CS, regardless of treatment history. Thus, chronic pre-exposure to methamphetamine did not alter sexual conditioning. In contrast, chronic pre-exposure to methamphetamine (3.0 mg/kg) decreased the frequency of successful copulations suggesting that it impaired sexual performance. The findings suggest that methamphetamine may differentially affect the neural circuitry involved in motivational systems compared with those involved in consummatory aspects of sexual behavior. These effects may last long after drug cessation.
在当前研究中,雄性鹌鹑每天一次腹腔注射甲基苯丙胺(3.0或5.6毫克/千克)或生理盐水,持续10天,并评估其运动活性。在31天的戒断期后,进行性条件反射试验,即在与雌性鹌鹑交配机会之前呈现条件刺激(CS)。用甲基苯丙胺(5.6毫克/千克)处理的雄性鹌鹑从试验1到试验10显示出运动活性下降,表明存在潜在的耐受效应。在31天的戒断期后,所有接受CS并伴有交配机会的雄性鹌鹑,无论其治疗史如何,都表现出对CS的接近增强。因此,长期预先接触甲基苯丙胺并未改变性条件反射。相比之下,长期预先接触甲基苯丙胺(3.0毫克/千克)降低了成功交配的频率,表明它损害了性行为表现。这些发现表明,与涉及性行为完成方面的神经回路相比,甲基苯丙胺可能对涉及动机系统的神经回路产生不同的影响。这些影响可能在药物停用后持续很长时间。