Salmon P, Stanford C, Gray J A
Psychopharmacology (Berl). 1985;87(1):77-80. doi: 10.1007/BF00431782.
First, it was confirmed that systemic injection of the neurotoxin 6-hydroxydopamine HBr (30 mg/kg IP) depleted noradrenaline levels in rat heart, but not centrally. Losses averaged 90% of control 1 day after injection, and 50% at 42 days. The same drug and dose was then administered to 50% of a group of rats which had been trained to lever-press for food reward on continuous reinforcement (CRF). After further CRF sessions, the rats were changed to a schedule of Differential Reinforcement of Low Rates of Response with a 20-s criterion (DRL 20). The drugged rats earned fewer reinforcements during DRL than did controls, and made fewer responses. Temporal discrimination (shown by the IRT/Opp distribution) was disrupted. It is concluded that peripheral noradrenergic systems may be involved in the control over responding by temporal cues associated with reward and non-reward.
首先，已证实腹腔注射神经毒素氢溴酸6-羟基多巴胺（30毫克/千克）可使大鼠心脏中的去甲肾上腺素水平降低，但不会使中枢去甲肾上腺素水平降低。注射后1天，损失平均为对照组的90%，42天时为50%。然后，将相同的药物和剂量给予一组经过训练在连续强化（CRF）条件下通过杠杆按压获取食物奖励的大鼠中的50%。在进一步的CRF训练阶段后，将大鼠改为采用20秒标准的低反应率差异强化（DRL 20）方案。与对照组相比，用药大鼠在DRL期间获得的强化物更少，反应也更少。时间辨别能力（通过IRT/Opp分布显示）受到干扰。得出的结论是，外周去甲肾上腺素能系统可能参与了与奖励和无奖励相关的时间线索对反应的控制。
