Optogenetic modulation of inhibition in cat visual cortex

猫视觉皮层抑制的光遗传学调节

• 批准号: 10341167
• 负责人: Diego Contreras
• 金额: $ 19.7万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10341167
• 关键词: Address; Adult; Animals; Brain; Budgets; Canis familiaris; Cells; Cellular Structures; Cortical Column; Data; Development; Electrophysiology (science); Enhancers; Exploratory/Developmental Grant; Felis catus; Funding; Future; Gene Delivery; Genes; Goals; Homeobox Genes; Image; Individual; Injections; Interneurons; Intrathecal Injections; Label; Light; Mammals; Measures; Mediating; Mental disorders; Methodology; Methods; Modeling; Mus; Neurons; Operative Surgical Procedures; Opsin; Output; Pattern; Pennsylvania; Primates; Property; Publications; Recombinant adeno-associated virus (rAAV); Role; Route; Schizophrenia; Site; Specificity; Stimulus; Techniques; Therapeutic; Time; Toxic effect; Universities; Veterinary Medicine; Veterinary Schools; Viral; Vision; Visual; Visual Cortex; Wages; Work; adeno-associated viral vector; area striata; base; cisterna magna; cost; experience; falls; gene therapy; in vivo; infection rate; neocortical; optogenetics; receptive field; response; retinotopic; scaffold; screening; selective expression; spatiotemporal; success; therapeutic evaluation; tool; transgene expression; vector; visual stimulus

PROJECT SUMMARY Image representation in primary visual cortex depends critically on the spatiotemporal pattern of activation of distributed visual cortical networks. Such activation relies on distribution of contrasts in the visual scene but also in part in the scaffolding of horizontal connections in supragranular layers 2-3 that connect cortical columns of similar orientation. For individual visual cortical cells their spatially well defined receptive field (RF) is not sufficient to explain their visual responses to visual scenes. Indeed, the context of visual stimuli falling outside of the RF is a critical component of the cell response. Such effects have been called contextual effects, they depend on the relative properties between the visual stimulus inside and outside of the RF and can be facilitatory, inhibitory or they can modulate the gain (the slope of the input-output function) of the neuron. A fundamental impediment to understanding the underlying mechanisms of contextual stimuli is the ability of manipulating inhibition at the mesoscale of the cortical column. Here, in Aim 1 we propose to implement in the cat optogenetic approaches that allow to manipulate inhibition with great temporal sensitivity. We will use a strategy developed recently based on the selective expression of the DLX homeobox gene enhancer mDlx in cortical GABAergic interneurons of all vertebrate species. We will procure (from the Penn Vector Core) and inject AAV vectors containing depolarizing (ChR2) and hyperpolarizing (ArchT) opsins under the control of mDLx. We will verify selective expression with electrophysiology and inmunohistochemistry and will calibrate the effect of blue and green light on the responses to visual stimuli and current injection of regular and fast spiking neurons recorded intracellularly in vivo. Work in Aim 1 will be done with the help of Dr. John Wolfe from the Veterinary School which is an expert in viral approaches for gene therapy. In Aim 2 we will obtain preliminary data on the role of GABAergic inhibition in surround suppression and gain modulation caused by contextual stimuli. In addition to strong preliminary data for a future R01 application this project will implement an approach that will allow addressing over 50 year old questions in a highly visual animal.

项目摘要 初级视皮层中的图像表征关键取决于 分布式视觉皮层网络。这种激活依赖于视觉场景中对比度的分布， 也部分地在连接皮质的颗粒上层2-3中的水平连接的支架中 相似方向的柱子。对于单个视皮层细胞，其空间上定义良好的感受野（RF） 不足以解释他们对视觉场景的视觉反应。事实上，视觉刺激下降的背景 在RF之外是细胞响应的关键组成部分。这种效应被称为语境效应， 它们取决于RF内部和外部视觉刺激之间的相对属性， 易化的、抑制的，或者它们可以调节神经元的增益（输入-输出函数的斜率）。一 理解背景刺激的潜在机制的根本障碍是 在皮质柱的中尺度操纵抑制。在这里，在目标1中，我们建议在 猫的光遗传学方法，允许操纵抑制具有很大的时间敏感性。我们将使用一个 最近开发的策略是基于DLX同源框基因增强子mDlx的选择性表达， 所有脊椎动物物种的皮质GABA能中间神经元。我们将获得（从宾州向量核心）， 注射含有去极化（ChR 2）和超极化（ArchT）视蛋白的AAV载体， mDLx。我们将通过电生理学和免疫组织化学验证选择性表达，并将校准 蓝光和绿色光对视觉刺激和电流注入的反应的影响 在体内细胞内记录的尖峰神经元。目标1中的工作将在约翰·沃尔夫博士的帮助下完成， 兽医学院是基因治疗病毒方法的专家。在Aim 2中，我们将获得 GABA能抑制在周围抑制和增益调制中作用的初步数据 情境刺激除了为未来的R 01应用提供强有力的初步数据外，该项目还将实施 这种方法将允许在高度视觉化的动物中解决超过50年的问题。