Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK; Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
Neuron. 2013 Sep 4;79(5):945-56. doi: 10.1016/j.neuron.2013.07.045.
In Drosophila, anatomically discrete dopamine neurons that innervate distinct zones of the mushroom body (MB) assign opposing valence to odors during olfactory learning. Subsets of MB neurons have temporally unique roles in memory processing, but valence-related organization has not been demonstrated. We functionally subdivided the αβ neurons, revealing a value-specific role for the ∼160 αβ core (αβc) neurons. Blocking neurotransmission from αβ surface (αβs) neurons revealed a requirement during retrieval of aversive and appetitive memory, whereas blocking αβc only impaired appetitive memory. The αβc were also required to express memory in a differential aversive paradigm demonstrating a role in relative valuation and approach behavior. Strikingly, both reinforcing dopamine neurons and efferent pathways differentially innervate αβc and αβs in the MB lobes. We propose that conditioned approach requires pooling synaptic outputs from across the αβ ensemble but only from the αβs for conditioned aversion.
在果蝇中，解剖上离散的多巴胺神经元支配蘑菇体（MB）的不同区域，在嗅觉学习过程中为气味赋予相反的效价。MB 神经元的亚群在记忆处理中具有时间上独特的作用，但尚未证明与效价相关的组织。我们对αβ神经元进行了功能细分，揭示了约 160 个αβ核心（αβc）神经元具有特定的价值作用。阻断αβ表面（αβs）神经元的神经传递揭示了在检索厌恶和食欲记忆时的需求，而阻断αβc 仅损害食欲记忆。αβc 还需要在差异厌恶范式中表达记忆，从而在相对估值和接近行为中发挥作用。引人注目的是，强化多巴胺神经元和传出途径都以不同的方式支配 MB 叶中的αβc 和αβs。我们提出，条件性接近需要从整个αβ集合中汇集突触输出，但仅从αβs 进行条件性厌恶。
