Duality of salience in dopamine neurons.
Duality of salience in dopamine neurons.
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多巴胺神经元的显着性的双重性。
DOI：
10.1073/pnas.0906641106
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发表时间：
2009
影响因子：
11.1
通讯作者：
Ma,Sisi
中科院分区：
文献类型：
--
作者：
Root,DavidH;Barker,DavidJ;Ma,Sisi
Brischoux等人(1)可能最终提供了必要的证据，以弥合多巴胺（DA）理论之间最近但发展良好的争议。数据分析的主要理论描述了食欲（2,3）或厌恶结果（4,5）的功能相关性，但在这些概念的十字路口却有所欠缺。多巴胺神经元在受到奖励时明显表现出放电速率的阶段性增加(2)，这可能会增加中边缘区域的多巴胺。尽管足震增加了中脑皮质和中边缘区的DA(4,5)，但尚未证实足震对腹侧被盖区（VTA）神经元放电率的阶段性增加(2)。Brischoux等人(1)证明，在研究较少的VTA腹侧部分，神经化学鉴定的DA神经元在脚震反应中表现出放电速率的阶段性增加，这表明中脑预后预测可能使用不同的模式。当然，大多数刺激，以及不同的强化时间表，都包含奖励和厌恶的性质。作者证明，VTA在厌恶刺激的开始和结束时都表现出放电率的增加，这可能具有强化特性，允许人们将理性应用于先前在DA理论中神秘的发现。例如，Young(5)表明，配对两种中性刺激会增加细胞外伏隔区DA。如果DA神经元发出阳性或阴性信号，Brischoux等人(1)的结果可以预测新刺激通常产生的新恐惧或兴奋反应。此外，与低努力寻找食物任务相比，高努力任务期间细胞外伏隔区DA浓度的增加(6)也可以用DA神经元信号的双重价来解释。也就是说，在高努力任务中增加的DA可能反映了增加的“反应”的惩罚特性
Brischoux et al.(1) may have finally provided the evidence necessary to bridge a recent, but well developed controversy between dopamine (DA) theories. Major theories of DA have described functional correlates for both appetitive (2, 3) or aversive outcomes (4, 5) but have fallen short at the crossroads of these concepts. DA neurons clearly exhibit phasic increases in firing rate in response to rewards (2), which presumably increases DA in mesolimbic regions. Although DA is increased by footshock in mesocortical and mesolimbic regions (4, 5), phasic increases in firing rate of ventral tegmental area (VTA) neurons in response to footshock have not been demonstrated (2). Brischoux et al.(1) demonstrate that, in the sparsely researched ventral portion of the VTA, neurochemically identified DA neurons exhibit phasic increases in firing rate in response to footshock, suggesting that mesencephalic outcome prediction might function using distinct modalities.Surely the majority of stimuli, as well as differing schedules of reinforcement, contain both rewarding and aversive properties. The author’s demonstration that the VTA exhibits increases in firing rates in response to both the onset of an aversive stimulus as well as its termination, which could have reinforcing properties, allows one to apply rationality to previously enigmatic findings among DA theories. For example, Young (5) has shown that the pairing of 2 neutral stimuli produces an increase in extracellular accumbal DA. If DA neurons signal positive or negative outcomes, the results of Brischoux et al.(1) may predict the neophobic or excitatory reactions typically generated by novel stimuli. Further, increased extracellular accumbal DA concentrations during high-effort as compared with low-effort food-seeking tasks (6) might also be explained by the dual valence of DA neuron signaling. That is, the increased DA in high-effort tasks might reflect the punishing properties of an increased ‘‘response