Biologisches Institut, Abteilung Tierphysiologie, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
Cogn Affect Behav Neurosci. 2012 Mar;12(1):74-84. doi: 10.3758/s13415-011-0068-4.
Decision-making policies are subject to modulation by changing motivational states. However, so far, little is known about the neurochemical mechanisms that bridge motivational states with decision making. Here we examined whether dopamine (DA) in the nucleus accumbens core (AcbC) modulates the effects of motivational states on effort-based decision making. Using a cost-benefit T-maze task in rats, we examined the effects of AcbC DA depletions on effort-based decision making, in particular on the sensitivity of effort-based decision making to a shift from a hungry to a sated state. The results demonstrated that, relative to sham controls, rats with AcbC DA depletion in a hungry as well as in a sated state had a reduced preference for effortful but large-reward action. This finding provides further support for the notion that AcbC DA regulates how much effort to invest for rewards. Importantly, our results further revealed that effort-based decision making in lesioned rats, as in sham controls, was still sensitive to a shift from a hungry to a sated state; that is, their preferences for effortful large-reward actions became lower after a shift from a restricted to a free-feeding regimen. These finding indicate that AcbC DA is not necessarily involved in mediating the effects of a shift in motivational state on decision-making policies.
决策策略受到不断变化的动机状态的调节。然而，到目前为止，对于将动机状态与决策联系起来的神经化学机制还知之甚少。在这里，我们研究了伏隔核核心（AcbC）中的多巴胺（DA）是否调节动机状态对基于努力的决策的影响。我们使用大鼠的成本效益 T 迷宫任务，研究了 AcbC DA 耗竭对基于努力的决策的影响，特别是对从饥饿状态转变为饱腹状态时基于努力的决策的敏感性的影响。结果表明，与假手术对照相比，饥饿和饱腹状态下 AcbC DA 耗竭的大鼠对费力但高回报的动作的偏好降低。这一发现进一步支持了这样一种观点，即 AcbC DA 调节了为奖励投入多少努力。重要的是，我们的结果还表明，与假手术对照相比，受损大鼠的基于努力的决策仍然对从饥饿状态到饱腹状态的转变敏感；也就是说，从限制喂养到自由喂养方案的转变后，他们对费力的高回报动作的偏好降低。这些发现表明，AcbC DA 不一定参与介导动机状态转变对决策策略的影响。
