Grilly D M, Gowans G C
Cleveland State University, Psychology Department, OH 44115.
Psychopharmacology (Berl). 1988;96(1):73-80. doi: 10.1007/BF02431536.
The hypothesis that endogenous opioid peptides modulate attentional processes was tested. The effects of the opioid antagonist naltrexone (NALT), d-amphetamine (AMP), and their interaction were investigated in rats trained in a two-choice task in which the position of a short-duration light served as a cue for food-reinforced responses. NALT (0.25, 1.0, 5.0, and 10.0 mg/kg) produced no significant changes in performance (accuracy, choice latency, and food retrieval time). As predicted, AMP induced dose-dependent biphasic effects. Low doses of AMP (0.25 and 0.5 mg/kg) significantly enhanced accuracy, decreased choice latency, and lengthened food retrieval time; 1.25 mg/kg AMP disrupted accuracy, increased choice latency, and further lengthened food retrieval time. The combination of NALT (0.25, 1.0, and 10.0 mg/kg) and subthreshold doses of AMP (0.07 and 0.1 mg/kg) had no effect on performance except for an increase in food retrieval time with 10.0 mg/kg NALT, whereas the combination of NALT and moderate doses of AMP (0.5 and 1.0 mg/kg) disrupted accuracy, increased choice latencies, and lengthened food retrieval time. These results do not support the hypothesis that endogenous opioid peptides play a vital role in attentional processes or that opioid antagonists may be useful in the treatment of attentional deficit disorders.
对内源性阿片肽调节注意力过程的假说进行了检验。在一项双选任务中对大鼠进行训练，其中短时光刺激的位置作为食物强化反应的线索，研究了阿片拮抗剂纳曲酮（NALT）、右旋苯丙胺（AMP）及其相互作用的影响。NALT（0.25、1.0、5.0和10.0毫克/千克）对行为表现（准确性、选择潜伏期和食物获取时间）没有产生显著变化。如预期的那样，AMP诱导了剂量依赖性的双相效应。低剂量的AMP（0.25和0.5毫克/千克）显著提高了准确性，缩短了选择潜伏期，并延长了食物获取时间；1.25毫克/千克的AMP破坏了准确性，增加了选择潜伏期，并进一步延长了食物获取时间。NALT（0.25、1.0和10.0毫克/千克）与阈下剂量的AMP（0.07和0.1毫克/千克）联合使用对行为表现没有影响，除了10.0毫克/千克的NALT使食物获取时间增加，而NALT与中等剂量的AMP（0.5和1.0毫克/千克）联合使用则破坏了准确性，增加了选择潜伏期，并延长了食物获取时间。这些结果不支持内源性阿片肽在注意力过程中起关键作用或阿片拮抗剂可能有助于治疗注意力缺陷障碍的假说。
