Punishment prediction by dopaminergic neurons in Drosophila
Punishment prediction by dopaminergic neurons in Drosophila
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DOI：
10.1016/j.cub.2005.09.042
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发表时间：
2005-11-08
期刊：
影响因子：
9.2
通讯作者：
Fiala, A
中科院分区：
文献类型：
--
作者：
Riemensperger, T;Völler, T;Fiala, A
中性刺激和增强器(奖励或惩罚)的时间配对可以导致经典的条件反射，这是一种简单的学习形式，动物为以前的中性刺激赋予一个值(积极或消极)[1]。果蝇的嗅觉经典条件作用是分析这种学习和记忆的分子和神经元底物的主要模型[2-5]。在昆虫大脑的几个区域中，已经发现了与联合可塑性有关的神经元。特别是，蘑菇体已被证明是形成厌恶嗅觉记忆所必需的[6]。然而，关于哪些神经元参与了增强刺激的调节，人们知之甚少。使用功能光学成像，我们现在表明，到蘑菇体叶的多巴胺能投射被气味刺激激活得很弱，但对电击有强烈的反应。然而，在两种气味中的一种与电击几次配对后，气味唤起的活动只对“受惩罚的”气味显著延长。虽然多巴胺能神经元在哺乳动物中介导奖励性强化[7]，但我们的数据表明，在果蝇中也有厌恶强化的作用。然而，在果蝇和哺乳动物之间，多巴胺能神经元调节和预测增强刺激的能力似乎是保守的。
The temporal pairing of a neutral stimulus with a reinforcer (reward or punishment) can lead to classical conditioning, a simple form of learning in which the animal assigns a value (positive or negative) to the formerly neutral stimulus [1]. Olfactory classical conditioning in Drosophila is a prime model for the analysis of the molecular and neuronal substrate of this type of learning and memory [2-5]. Neuronal correlates of associative plasticity have been identified in several regions of the insect brain. In particular, the mushroom bodies have been shown to be necessary for aversive olfactory memory formation [6]. However, little is known about which neurons mediate the reinforcing stimulus. Using functional optical imaging, we now show that dopaminergic projections to the mushroom-body lobes are weakly activated by odor stimuli but respond strongly to electric shocks. However, after one of two odors is paired several times with an electric shock, odor-evoked activity is significantly prolonged only for the "punished" odor. Whereas dopaminergic neurons mediate rewarding reinforcement in mammals [7], our data suggest a role for aversive reinforcement in Drosophila. However, the dopaminergic neurons' capability of mediating and predicting a reinforcing stimulus appears to be conserved between Drosophila and mammals.