Dissociations between interval timing and intertemporal choice following administration of fluoxetine, cocaine, or methamphetamine
Dissociations between interval timing and intertemporal choice following administration of fluoxetine, cocaine, or methamphetamine
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DOI：
10.1016/j.beproc.2013.09.013
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发表时间：
2014-01-01
影响因子：
1.3
通讯作者：
Meck, Warren H.
中科院分区：
文献类型：
--
作者：
Heilbronner, Sarah R.;Meck, Warren H.
我们研究的目的是描述跨期选择和间隔时间之间的关系，包括确定调节大脑5-羟色胺和多巴胺水平的药物如何影响这两个过程。在实验I中，在氟西汀（3、5或8 mg/kg）或溶剂给药后，对大鼠进行标准40 s峰间期程序测试，以评估对间期时间的基本影响。在实验2中，大鼠进行了测试，在一个新的行为模式，旨在同时检查间隔时间和冲动。大鼠进行了一个变种的双峰程序使用10秒和40秒的目标持续时间与额外的“叛逃”杠杆，提供了一个小的，立即奖励的可能性。计时功能保持相对完整，受试者的“耐心”与高峰时间相关，表明“耐心”与时钟速度之间存在负相关关系。我们接下来检查了氟西汀（5 mg/kg）、可卡因（15 mg/kg）或甲基苯丙胺（1 mg/kg）对任务表现的影响。氟西汀降低了冲动性，这是通过检测时间来衡量的，而没有相应的时钟速度变化。相比之下，可卡因和甲基苯丙胺都增加了冲动和时钟速度。因此，时间的变化可能通过多巴胺能输入介导跨期选择。然而，一个单独的，神经元能系统可以影响跨时间的选择，而不直接影响间隔时间。(C)2013爱思唯尔有限公司版权所有。
The goal of our study was to characterize the relationship between intertemporal choice and interval timing, including determining how drugs that modulate brain serotonin and dopamine levels influence these two processes. In Experiment I, rats were tested on a standard 40-s peak-interval procedure following administration of fluoxetine (3, 5, or 8 mg/kg) or vehicle to assess basic effects on interval timing. In Experiment 2, rats were tested in a novel behavioral paradigm intended to simultaneously examine interval timing and impulsivity. Rats performed a variant of the bi-peak procedure using 10-s and 40-s target durations with an additional "defection" lever that provided the possibility of a small, immediate reward. Timing functions remained relatively intact, and 'patience' across subjects correlated with peak times, indicating a negative relationship between 'patience' and clock speed. We next examined the effects of fluoxetine (5 mg/kg), cocaine (15 mg/kg), or methamphetamine (1 mg/kg) on task performance. Fluoxetine reduced impulsivity as measured by defection time without corresponding changes in clock speed. In contrast, cocaine and methamphetamine both increased impulsivity and clock speed. Thus, variations in timing may mediate intertemporal choice via dopaminergic inputs. However, a separate, serotonergic system can affect intertemporal choice without affecting interval timing directly.This article is part of a Special Issue entitled: Associative and Temporal Learning. (C) 2013 Elsevier B.V. All rights reserved.