Voltage dynamics of distinct cortical ensembles in visually guided behavior

摘要 BRAIN Initiative资助的大规模方法，根据转录组学，形态学和 电特性揭示了小鼠大脑中数十种独特的细胞类别。然而，无论他们 代表与动物感知和行为相关的功能多样的种群仍然是一个开放的 问题剖析他们各自的角色需要整合有针对性的记录技术， 光遗传学操纵方法，其在生理学相关的时空尺度上操作（即， 蜂窝分辨率和毫秒时间尺度）。 在这里，我们建议使用高速（0.4-1 kHz），基因编码的荧光电压成像， 理解不同的中间神经元群体在视觉处理的注意力调节中的作用， 视觉引导行为。首先，我们将建立高速、双通道电压的光学仪器 利用非重叠结构化照明成像。我们将进一步验证第二代产品的使用， 荧光共振能量转移（FRET）-视蛋白指示剂Ace-mNeon 2和VARNAM 2及其逆转 响应极性变体pAce和pAceR，用于从神经元间对同时记录电压 集合体和锥体神经元。此后，使用同时三重人口 电压成像，我们将评估在视觉过程中注意力对三类细胞放电率的影响。 引导行为，并计算相邻神经元激活模式的时空相关性。 另外，我们将测量相同神经元在呈现漂移时的视觉调谐特性 刺耳的刺激我们将进一步得出神经元注意调制指数与特征之间的相关性 选择性来测试特征相似性增益模型的适用性。最后，为了确定因果关系， 注意力调节的视觉反应，我们将光遗传学操纵的活动选择interneurons 在空间上精确的方式，同时记录相邻的锥体细胞的电压响应，当小鼠 参与到行为任务中。 我们提出的工作将（1）阐明不同类型的中间神经元在视觉注意中的作用， 在相同的动物和增加的时空分辨率内进行功能交叉比较;（2）揭示 神经元相邻锥体神经元-中间神经元对之间的协同和拮抗关系 （3）测试特征相似性增益的适用性 模型和（4）建立因果关系的不同interneuronal群体在注意力调制的 视觉处理 总之，我们的工作将建立同步，多群体电压成像作为首选的方式 来揭示神经元类型在感知和行为方面的实时功能差异。

ABSTRACT BRAIN Initiative-funded, large-scale approaches to classify neurons based on transcriptomic, morphological and electrical properties have unveiled dozens of unique cell classes in the mouse brain. However, whether they represent functionally diverse populations of relevance to animal perception and behavior remains an open question. Dissecting their individual roles requires the integration of targeted recording techniques and optogenetic manipulation approaches, which operate at the physiologically relevant spatiotemporal scales (i.e. cellular resolution and millisecond timescales). Here, we propose to use high-speed (0.4-1 kHz), genetically encoded fluorescence voltage imaging to understand the role of distinct interneuronal populations in attentional modulation of visual processing during visually guided behavior. First, we will establish the optical instrumentation for high-speed, dual channel voltage imaging with non-overlapping structured illumination. We will further validate the use of our second-generation, fluorescence resonance energy transfer (FRET)-opsin indicators Ace-mNeon2 and VARNAM2 and their reverse response polarity variants pAce and pAceR, for concurrent voltage recordings from pairs of interneuronal ensembles and pyramidal neurons in awake, running mice. Thereafter, using simultaneous triple-population voltage imaging, we will assess the effects of attention on the firing rates of the three cell classes during visually guided behavior and compute the spatiotemporal correlations in the activation patterns of neighboring neurons. Separately, we will measure the visual tuning properties of the same neurons during presentations of drifting grating stimuli. We will further draw a correlation between neuronal attention modulation index and feature selectivity to test the applicability of the feature similarity gain model. Lastly, to establish causal roles in the attentional modulation of visual responses, we will optogenetically manipulate the activity of select interneurons in a spatially precise manner, while recording the voltage responses in neighboring pyramidal cells when mice are engaged in the behavioral task. Our proposed work will (1) elucidate the role of distinct interneuron-types in visual attention and enable functional cross-comparisons within the same animals and at increased spatiotemporal resolution; (2) uncover synergistic and antagonistic relationships between neighboring pyramidal neuron-interneuron pairs for neurons that are positively versus negatively modulated by attention; (3) test the applicability of the feature similarity gain model in rodents and (4) establish causal roles for distinct interneuronal populations in attentional modulation of visual processing. Together, our work will establish simultaneous, multipopulation voltage imaging as the preferred modality to unravel the real-time functional differences between neuron-types in perception and behavior.