Department of Molecular Neurobiology of Behavior, Johann-Friedrich-Blumenbach-Institute for Zoology and Anthropology, University of Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany.
Department of Cellular Neurobiology, Johann-Friedrich-Blumenbach-Institute for Zoology and Anthropology, University of Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany.
Neuron. 2020 Jun 17;106(6):963-976.e4. doi: 10.1016/j.neuron.2020.03.010. Epub 2020 Apr 7.
During associative conditioning, animals learn which sensory cues are predictive for positive or negative conditions. Because sensory cues are encoded by distributed neurons, one has to monitor plasticity across many synapses to capture how learned information is encoded. We analyzed synaptic boutons of Kenyon cells of the Drosophila mushroom body γ lobe, a brain structure that mediates olfactory learning. A fluorescent Ca sensor was expressed in single Kenyon cells so that axonal boutons could be assigned to distinct cells and Ca could be measured across many animals. Learning induced directed synaptic plasticity in specific compartments along the axons. Moreover, we show that odor-evoked Ca dynamics across boutons decorrelate as a result of associative learning. Information theory indicates that learning renders the stimulus representation more distinct compared with naive stimuli. These data reveal that synaptic boutons rather than cells act as individually modifiable units, and coherence among them is a memory-encoding parameter.
在关联条件作用过程中，动物学习哪些感觉线索可以预测积极或消极的条件。由于感觉线索是由分布的神经元编码的，因此必须监测许多突触之间的可塑性，以捕捉学习信息的编码方式。我们分析了果蝇蘑菇体γ叶的 Kenyon 细胞的突触末梢，该大脑结构介导嗅觉学习。在单个 Kenyon 细胞中表达了一种荧光 Ca 传感器，以便可以将轴突末梢分配给不同的细胞，并可以在许多动物中测量 Ca。学习诱导了特定轴突区域的定向突触可塑性。此外，我们还表明，由于联想学习，气味诱发的 Ca 动力学在末梢之间解相关。信息论表明，与原始刺激相比，学习使刺激表示更加独特。这些数据表明，突触末梢而不是细胞作为可单独修饰的单元起作用，它们之间的相干性是记忆编码的参数。
