Jang Hyun Jae, Chung Hyowon, Rowland James M, Richards Blake A, Kohl Michael M, Kwag Jeehyun
Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
Sci Adv. 2020 Apr 22;6(17):eaay5333. doi: 10.1126/sciadv.aay5333. eCollection 2020 Apr.
Synchronization of precise spike times across multiple neurons carries information about sensory stimuli. Inhibitory interneurons are suggested to promote this synchronization, but it is unclear whether distinct interneuron subtypes provide different contributions. To test this, we examined single-unit recordings from barrel cortex in vivo and used optogenetics to determine the contribution of parvalbumin (PV)- and somatostatin (SST)-positive interneurons to the synchronization of spike times across cortical layers. We found that PV interneurons preferentially promote the synchronization of spike times when instantaneous firing rates are low (<12 Hz), whereas SST interneurons preferentially promote the synchronization of spike times when instantaneous firing rates are high (>12 Hz). Furthermore, using a computational model, we demonstrate that these effects can be explained by PV and SST interneurons having preferential contributions to feedforward and feedback inhibition, respectively. Our findings demonstrate that distinct subtypes of inhibitory interneurons have frequency-selective roles in the spatiotemporal synchronization of precise spike times.
多个神经元之间精确的尖峰时间同步携带有关感觉刺激的信息。有研究表明抑制性中间神经元会促进这种同步，但尚不清楚不同的中间神经元亚型是否有不同的作用。为了验证这一点，我们检查了体内桶状皮质的单神经元记录，并使用光遗传学来确定小清蛋白（PV）阳性和生长抑素（SST）阳性中间神经元对跨皮质层尖峰时间同步的作用。我们发现，当瞬时放电率较低（<12赫兹）时，PV中间神经元优先促进尖峰时间的同步，而当瞬时放电率较高（>12赫兹）时，SST中间神经元优先促进尖峰时间的同步。此外，我们使用计算模型证明，这些效应可以分别由PV和SST中间神经元对前馈抑制和反馈抑制的优先作用来解释。我们的研究结果表明，抑制性中间神经元的不同亚型在精确尖峰时间的时空同步中具有频率选择性作用。
