Sparse Representation in Awake Auditory Cortex: Cell-type Dependence, Synaptic Mechanisms, Developmental Emergence, and Modulation
Sparse Representation in Awake Auditory Cortex: Cell-type Dependence, Synaptic Mechanisms, Developmental Emergence, and Modulation
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清醒听觉皮层的稀疏表示：细胞类型依赖性、突触机制、发育出现和调节
DOI：
10.1093/cercor/bhy260
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发表时间：
2019-09-01
期刊：
影响因子：
3.7
通讯作者：
Zhang, Li I.
中科院分区：
文献类型：
--
作者：
Liang, Feixue;Li, Haifu;Zhang, Li I.
稀疏表示被认为是各种感觉通道中皮层处理的重要编码策略。目前尚不清楚皮质稀疏是如何产生的，以及如何受到调控。在这里，来自清醒成年小鼠初级听觉皮质的无偏记录显示出显著的层稀疏(L)2/3，大多数兴奋性神经元对每种测试的声音类型没有表现出增加的尖峰反应。在小白蛋白(PV)抑制神经元中未观察到稀疏表达。无反应的神经元确实接受了听觉诱发的突触输入，其特点是兴奋较弱，兴奋/抑制比(E/I)较反应细胞低。稀疏表征在发育过程中以经验依赖的方式出现，伴随着兴奋性输入强度的不同变化以及E/I比从单峰分布向双峰分布的转变。抑制PV或L1抑制神经元可降低稀疏程度。因此，稀疏表征可以通过调节E/I平衡来动态调节，从而优化外部感觉世界的皮质表征。
Sparse representation is considered an important coding strategy for cortical processing in various sensory modalities. It remains unclear how cortical sparseness arises and is being regulated. Here, unbiased recordings from primary auditory cortex of awake adult mice revealed salient sparseness in layer (L)2/3, with a majority of excitatory neurons exhibiting no increased spiking in response to each of sound types tested. Sparse representation was not observed in parvalbumin (PV) inhibitory neurons. The nonresponding neurons did receive auditory-evoked synaptic inputs, marked by weaker excitation and lower excitation/inhibition (E/I) ratios than responding cells. Sparse representation arises during development in an experience-dependent manner, accompanied by differential changes of excitatory input strength and a transition from unimodal to bimodal distribution of E/I ratios. Sparseness level could be reduced by suppressing PV or L1 inhibitory neurons. Thus, sparse representation may be dynamically regulated via modulating E/I balance, optimizing cortical representation of the external sensory world.