Optimizing optogenetic stimulation protocols in auditory corticofugal neurons based on closed-loop spike feedback.
Optimizing optogenetic stimulation protocols in auditory corticofugal neurons based on closed-loop spike feedback.
复制标题
基于闭环尖峰反馈优化听觉皮质神经元的光遗传学刺激方案。
DOI：
10.1088/1741-2552/ab39cf
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发表时间：
2019
影响因子：
4
通讯作者：
Polley,DanielB
中科院分区：
文献类型：
--
作者：
Vila,Charles-Henri;Williamson,RossS;Hancock,KennethE;Polley,DanielB
光遗传学提供了一种探测大脑区域之间功能联系的方法。通过激活一组突触前神经元并记录下游大脑区域的活动，人们可以建立前馈连接的符号和强度。一个挑战是，几乎有无限的模式可以用来刺激突触前大脑区域。对下游大脑区域的功能影响不仅取决于突触前神经元是否被激活，还取决于它们是如何被激活的。来自听觉皮层的离皮质轴突（ACtx）主要支配听顶盖，下丘（IC）。在这里，我们试图确定不同模式的corticcollicular激活是否可以滴定的强度前馈调制的声音处理IC neurons.ApproachWe使用多通道电生理学和光遗传学记录从多个地区的IC清醒的头部固定的小鼠，而光遗传学刺激ACtx神经元表达Chronos，超快通道视紫红质。为了识别与对IC放电率的最强影响相关的皮层激活模式，我们采用了一种闭环进化优化程序，该程序基于来自单个IC神经元的尖峰反馈来定制发送到激光器的电压命令信号。我们的进化搜索程序集中在ACtx刺激配置上，该配置比一般激活产生更有效和更广泛的IC单位活性增强参数皮质调制中脑尖峰是双向的，作为进化搜索程序可以编程收敛于激活模式，无论是抑制或增强声音诱发IC firing rate.SignificanceThis研究介绍了一个闭环优化程序，探测功能之间的连接大脑区域。我们的研究结果表明，下行反馈投射对皮层下感觉处理的影响可以在信号和程度上有所不同，这取决于皮层神经元如何及时激活。
ObjectiveOptogenetics provides a means to probe functional connections between brain areas. By activating a set of presynaptic neurons and recording the activity from a downstream brain area, one can establish the sign and strength of a feedforward connection. One challenge is that there are virtually limitless patterns that can be used to stimulate a presynaptic brain area. Functional influences on downstream brain areas can depend not just on whether presynaptic neurons were activated, but how they were activated. Corticofugal axons from the auditory cortex (ACtx) heavily innervate the auditory tectum, the inferior colliculus (IC). Here, we sought to determine whether different modes of corticocollicular activation could titrate the strength of feedforward modulation of sound processing in IC neurons.ApproachWe used multi-channel electrophysiology and optogenetics to record from multiple regions of the IC in awake head-fixed mice while optogenetically stimulating ACtx neurons expressing Chronos, an ultra-fast channelrhodopsin. To identify cortical activation patterns associated with the strongest effects on IC firing rates, we employed a closed-loop evolutionary optimization procedure that tailored the voltage command signal sent to the laser based on spike feedback from single IC neurons.Main resultsWithin minutes, our evolutionary search procedure converged on ACtx stimulation configurations that produced more effective and widespread enhancement of IC unit activity than generic activation parameters. Cortical modulation of midbrain spiking was bi-directional, as the evolutionary search procedure could be programmed to converge on activation patterns that either suppressed or enhanced sound-evoked IC firing rate.SignificanceThis study introduces a closed-loop optimization procedure to probe functional connections between brain areas. Our findings demonstrate that the influence of descending feedback projections on subcortical sensory processing can vary both in sign and degree depending on how cortical neurons are activated in time.