Determinants of Signal Characteristics in a Retinal Network: Contribution of Local Field Potentials and Spike Trains.

在我的实验室里进行的团队研究有一个共同的目标，那就是更好地理解视网膜上不同细胞群的神经活动是如何将视觉刺激转化为大脑可以理解的神经密码的。多年来，我们一直在使用视网膜电图（ERG），一种在角膜表面非侵入性收集的复合信号，来解读不同细胞群的相对贡献。最近，我们在多电极阵列（MEA）方面获得了专业知识，该技术允许离体（分离的视网膜）记录eg样信号和神经节细胞的峰值活动，神经节细胞产生视网膜的传出信息。利用神经递质a-/拮抗剂的经典药典，我们已经记录了复合ERG信号中发生的多种相互作用，特别是在rgc和双极细胞水平上，这是ERG信号的两个主要贡献者。最近，我们开发了一种创新的免疫学方法来选择性地靶向电压门控钠通道的特定亚型。这种新颖的方法将使我们能够破译树突整合和spike生成在整个视网膜加工过程中的作用。在接下来的几年里，我们打算利用这项新技术来进一步了解如何对光强度的漫射变化进行整合（串行整合），以及视觉场景的各个部分如何相互作用（横向整合）以形成有意义的传出信息。我们也将开始研究构成视网膜的简单整合神经丛如何能够处理由视觉场景产生的天文数字的信息量。为此，我们将分析由MEA的64个记录通道并行捕获的视网膜活动，并通过将传递熵、相干估计或降维和种群活动时间过程等节能处理算法应用于复杂刺激产生的神经编码来研究数据。

The teamwork research taking place in my lab share the common objective of a better comprehension of how the neural activity of the various cell populations of the retina translates a visual stimulus into a neural code that can be understood by the brain. We have been using for many years the electroretinogram (ERG), a composite signal collected non-invasively at the surface of the cornea, to decipher the relative contribution of different cell population. More recently, we have gained expertise in the multi electrode array (MEA), a technology that allows the ex-vivo (isolated retina) recording of both the ERG-like signal and the spiking activity of the ganglion cells, the population giving rise to the efferent message of the retina.  Using the classical pharmacopeia of neurotransmitter a-/antagonists, we have documented many types of interactions occurring in the composite ERG signal, particularly at the level of the RGCs and the bipolar cells, two major contributors to the ERG signal. More recently, we have developed a innovative immunological method to selectively target specific isoforms of the Voltage-Gated Sodium Channels. This novel method shall allow us to decipher the role of dendritic integration and spike generation in the overall retinal processing. It is our intention in the next few years to capitalize on this new technique to further our knowledge on how integration takes place in response to diffuse changes in light intensities (serial integration) and how various parts of a visual scene interplay (lateral integration) to form a meaningful efferent message. We will also start investigating how the simple integrative plexus that constitutes the retina is capable of processing the astronomical amount of information generated by a visual scene. For that purpose, we will analyze the retinal activity captured in parallel by the 64 recording channels of the MEA and investigate the data by applying energy-saving processes algorithms such as transfer entropy, coherence estimation or dimension reduction and population activity time-course to the neural code generated by complex stimuli.