Voltage dynamics of distinct cortical ensembles in visually guided behavior

摘要 大脑倡议资助的大规模方法，根据转录、形态和 电学特性揭示了小鼠大脑中数十个独特的细胞类别。然而，他们是否 代表与动物感知和行为相关的功能多样化的种群仍然是开放的 问题。剖析他们的个别角色需要有针对性的记录技术和 光遗传操作方法在生理上相关的时空尺度(即 细胞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)、遗传编码的荧光电压成像来 了解不同的神经元间群体在视觉加工的注意调节中的作用 视觉引导的行为。首先，我们将建立高速、双通道电压的光学仪器 使用非重叠结构照明的成像。我们将进一步验证我们的第二代， 荧光共振能量转移-光学指示剂Ace-mNeon2和VARNAM2及其反向 反应极性变化的起搏和起搏器，用于来自成对神经元间的同步电压记录 清醒的跑步小鼠的群体和锥体神经元。此后，使用同时三种群 电压成像，我们将评估注意对三类细胞在视觉上的放电率的影响 引导行为，并计算相邻神经元激活模式的时空相关性。 另外，我们将在呈现漂移时测量相同神经元的视觉调谐特性 格栅刺激。我们将进一步得出神经元注意调制指数与特征之间的关系 选择性检验特征相似度增益模型的适用性。最后，确立因果关系在 视觉反应的注意调节，我们将从光遗传学的角度操纵选定的中间神经元的活动 以空间精确的方式，同时记录相邻锥体细胞的电压响应 都在从事行为任务。 我们提出的工作将(1)阐明不同的中间神经元类型在视觉注意中的作用，并使 在相同动物内和在提高时空分辨率的情况下进行功能交叉比较；(2)发现 相邻锥体神经元-中间神经元对神经元的协同和拮抗关系 被注意正向调制和负向调制；(3)检验特征相似性增益的适用性 啮齿动物模型和(4)建立不同神经元间群体在注意调节中的因果作用 视觉处理。 我们的工作将使同步、多种群电压成像成为首选方式 揭示不同类型神经元在感知和行为上的实时功能差异。

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.