Layer-Specific Refinement of Sensory Coding in Developing Mouse Barrel Cortex
Layer-Specific Refinement of Sensory Coding in Developing Mouse Barrel Cortex
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DOI：
10.1093/cercor/bhw280
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发表时间：
2017-10-01
期刊：
影响因子：
3.7
通讯作者：
Helmchen, Fritjof
中科院分区：
文献类型：
--
作者：
van der Bourg, Alexander;Yang, Jenq-Wei;Helmchen, Fritjof
啮齿动物有节奏的搅拌行为在出生后2周左右的关键时期成熟。在这个发展时期的新皮层电路的功能适应仍然知之甚少。在这里，我们描述了搅拌行为开始之前、期间和之后小鼠桶状皮质所有层的刺激诱发的神经元活动。采用多电极记录和双光子钙成像在麻醉小鼠，我们测试的反应，rostrocaudal胡须偏转，轴向“轻敲”刺激，以及它们的组合从出生后第10天（P10）至P28。在此期间，胡须诱发的神经元活动显示在第2/3层（L2/3）和L4普遍减少，但在L5和L 6增加。在类似于5 Hz的刺激2-s期间，神经元反应适应的明显改变伴随着这些变化。此外，单单元分析表明，响应选择性，有利于无论是横向偏转或轴向攻丝出现在更深的层内的关键时期P14左右。对于浅层，我们证实了这一发现，使用钙成像的L2/3神经元，这也表现出出现的反应选择性，以及逐步稀疏化和去相关的诱发反应P14左右。我们的研究结果表明，在小鼠体感皮层的感觉反应性和反应选择性层特异性的发展与探索行为的发病相一致。
Rodent rhythmic whisking behavior matures during a critical period around 2 weeks after birth. The functional adaptations of neocortical circuitry during this developmental period remain poorly understood. Here, we characterized stimulus-evoked neuronal activity across all layers of mouse barrel cortex before, during, and after the onset of whisking behavior. Employing multi-electrode recordings and 2-photon calcium imaging in anesthetized mice, we tested responses to rostrocaudal whisker deflections, axial "tapping" stimuli, and their combination from postnatal day 10 (P10) to P28. Within this period, whisker-evoked activity of neurons displayed a general decrease in layer 2/3 (L2/3) and L4, but increased in L5 and L6. Distinct alterations in neuronal response adaptation during the 2-s period of stimulation at similar to 5 Hz accompanied these changes. Moreover, single-unit analysis revealed that response selectivity in favor of either lateral deflection or axial tapping emerges in deeper layers within the critical period around P14. For superficial layers we confirmed this finding using calcium imaging of L2/3 neurons, which also exhibited emergence of response selectivity as well as progressive sparsification and decorrelation of evoked responses around P14. Our results demonstrate layer-specific development of sensory responsiveness and response selectivity in mouse somatosensory cortex coinciding with the onset of exploratory behavior.