Grilly D M, Pistell P J
Department of Psychology, Cleveland State University, Ohio 44115, USA.
Pharmacol Biochem Behav. 1997 Mar;56(3):515-22. doi: 10.1016/s0091-3057(96)00330-9.
The potential modulating influence of fluoxetine (FLU) on the effects of cocaine (COC) on vigilance task performance was explored. Rats were trained in a discrete-trial task in which pressing one of two levers was reinforced by food, with the correct lever indicated by the position of a briefly illuminated light. Tests with FLU (2.5, 5.0, and 10.0 mg/kg) revealed no significant effects of FLU on mean choice accuracy, log choice reaction time, or number of omission trials; however, 10.0 mg/kg FLU did produce a small but reliable increase in mean log food retrieval latency. The effects of COC (1.25, 2.5 and 10.0 mg/kg) were then assessed following pretreatment with saline or FLU (2.5 and 10.0 mg/kg). COC increased mean choice accuracy, with maximal performance enhancement occurring with 2.5 mg/kg COC; mean log choice reaction time was decreased by all three doses of COC, although there was considerable within-subject variability at the 10.0 mg/kg dose of COC. Pretreatment with FLU reversed both of these performance-enhancing effects of COC in a dose-dependent fashion. Log food retrieval latency was not significantly affected by the lower doses of COC and was significantly increased by the 10.0 mg/kg dose of COC. FLU and COC appeared to interact in an additive fashion with this measure. The number of omission trials per session was significantly increased by 10.0 mg/kg COC--an effect that was not significantly altered by FLU pretreatment. These results support previous studies indicating that acute FLU exposure can reduce many of COC's properties that may contribute to COC's efficacy as a positive reinforcer.
探讨了氟西汀（FLU）对可卡因（COC）在警觉任务表现方面影响的潜在调节作用。大鼠在一项离散试验任务中接受训练，按压两个杠杆之一可获得食物强化，正确的杠杆由短暂亮起的灯光位置指示。对FLU（2.5、5.0和10.0mg/kg）的测试显示，FLU对平均选择准确性、对数选择反应时间或遗漏试验次数均无显著影响；然而，10.0mg/kg的FLU确实使平均对数食物获取潜伏期有小幅但可靠的增加。在用生理盐水或FLU（2.5和10.0mg/kg）预处理后，评估了COC（1.25、2.5和10.0mg/kg）的作用。COC提高了平均选择准确性，2.5mg/kg的COC产生了最大的性能增强效果；所有三个剂量的COC均降低了平均对数选择反应时间，尽管在10.0mg/kg剂量的COC时，个体内存在相当大的变异性。FLU预处理以剂量依赖性方式逆转了COC的这两种性能增强作用。较低剂量的COC对对数食物获取潜伏期没有显著影响，而10.0mg/kg剂量的COC使其显著增加。FLU和COC在这一指标上似乎以相加的方式相互作用。每节试验中的遗漏试验次数因10.0mg/kg的COC而显著增加——这一效应未因FLU预处理而显著改变。这些结果支持了先前的研究，表明急性暴露于FLU可降低许多可能有助于COC作为阳性强化剂发挥作用的特性。
