HHMI Janelia Research Campus, Ashburn, VA, USA.
Department of Zoology, University of Cambridge, Cambridge, UK.
Nat Neurosci. 2020 Apr;23(4):544-555. doi: 10.1038/s41593-020-0607-9. Epub 2020 Mar 23.
Dopaminergic neurons (DANs) drive learning across the animal kingdom, but the upstream circuits that regulate their activity and thereby learning remain poorly understood. We provide a synaptic-resolution connectome of the circuitry upstream of all DANs in a learning center, the mushroom body of Drosophila larva. We discover afferent sensory pathways and a large population of neurons that provide feedback from mushroom body output neurons and link distinct memory systems (aversive and appetitive). We combine this with functional studies of DANs and their presynaptic partners and with comprehensive circuit modeling. We find that DANs compare convergent feedback from aversive and appetitive systems, which enables the computation of integrated predictions that may improve future learning. Computational modeling reveals that the discovered feedback motifs increase model flexibility and performance on learning tasks. Our study provides the most detailed view to date of biological circuit motifs that support associative learning.
多巴胺能神经元（DANs）在动物界中驱动学习，但调节它们活动从而学习的上游电路仍知之甚少。我们提供了果蝇幼虫学习中心蘑菇体中所有 DANs 的突触分辨率连接组图谱。我们发现了传入的感觉途径和一大群神经元，它们从蘑菇体输出神经元提供反馈，并连接不同的记忆系统（厌恶和渴望）。我们将其与 DANs 及其突触前伙伴的功能研究以及全面的电路建模相结合。我们发现 DANs 比较来自厌恶和渴望系统的会聚反馈，这使得可以计算出可能改善未来学习的综合预测。计算模型表明，发现的反馈模式增加了模型在学习任务中的灵活性和性能。我们的研究提供了迄今为止最详细的支持联想学习的生物电路模式视图。
