Using functionally-defined glomeruli to probe circuit function in the mammalian olfactory bulb

使用功能定义的肾小球探测哺乳动物嗅球的电路功能

• 批准号: 10468288
• 负责人: DALE M WACHOWIAK
• 金额: $ 38.47万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10468288
• 关键词: Adaptive Behaviors; Afferent Neurons; Animals; Behavior; Behavioral Assay; Biological Models; Brain; Cells; Code; Communities; Complex; Data; Detection; Diagnostic; Dorsal; Goals; Image; Individual; Interneurons; Knowledge; Lateral; Lead; Maps; Mediating; Modality; Modeling; Nature; Nervous system structure; Neurons; Neurosciences; Odorant Receptors; Odors; Olfactory Pathways; Organ; Output; Play; Population; Positioning Attribute; Problem Solving; Process; Property; Resources; Role; Sensory; Sensory Process; Shapes; Smell Perception; Specificity; Stimulus; System; Testing; Therapeutic; Time; behavioral response; cell type; driving behavior; experience; experimental study; glomerular function; improved; in vivo; information processing; innovation; insight; network models; neural circuit; novel; olfactory bulb; olfactory bulb glomeruli; olfactory sensory neurons; olfactory stimulus; operation; predictive modeling; relating to nervous system; response; sensory input; sensory prosthesis; sensory system; transmission process

PROJECT SUMMARY We seek to better understand how the brain processes olfactory information by focusing on how circuits of the olfactory bulb control two fundamental aspects of sensory processing: the relationship between sensory input and olfactory bulb output as a function of stimulus intensity, and tuning of response specificity by lateral inhibition. Models of how olfactory bulb circuits mediate these operations exist, but generating and testing rigorous predictions from them has been limited by a lack of understanding of how circuits are organized with respect to olfactory bulb glomeruli. Glomeruli represent individual odorant receptors and so constitute the fundamental unit of information processing at this stage. Our strategy is to overcome this gap by, first, better defining the functional map of odor 'space' across glomeruli of the dorsal olfactory bulb. To achieve this we will functionally define glomeruli in terms of the odorants to which they have maximal sensitivity as well as their relative sensitivities across a carefully-selected odorant panel, yielding the first `odor sensitivity' map of the dorsal olfactory bulb and allowing for the rapid and reliable identification of individual glomeruli across animals. We will use these data to uncover new insights into the organization of glomerular odor maps and to generate a public resource for further exploration by the neuroscience community. We will next use this knowledge to rigorously test alternative models for how specific circuits shape the input-output functions of the olfactory bulb by comparing intensity-response functions of sensory inputs and glomerular outputs and by selectively removing particular interneuron types from the olfactory bulb network. We will also test alternative models for how inhibitory connections between different glomeruli are organized and how they may be shaped by odor experience, using odorants that selectively activate different combinations of identified glomeruli. Our experimental strategy builds on innovative approaches that are key to achieving a new level of understanding of how odor representations are transformed by olfactory bulb circuits. First, we are able to repeatedly identify and target many glomeruli across the dorsal olfactory bulb using a small number of diagnostic odorants and to efficiently map responses to many odorants in a single experiment. Second, we are able to selectively image from sensory inputs to glomeruli, projection neuron outputs from glomeruli, or both simultaneously, allowing us to precisely characterize input-output transformations by olfactory circuits. Finally, we will develop an improved model of the olfactory bulb network that is highly constrained by experimental data and which should lead to new insights into how this network alters odor representations and enable new predictions that can be tested with further circuit manipulations or behavioral assays.

项目摘要 我们寻求通过关注电路的方式来更好地了解大脑如何处理嗅觉信息 嗅球控制感觉处理的两个基本方面：感觉之间的关系 输入和嗅球输出随刺激强度的函数，并通过横向调整响应特异性 抑制。嗅球电路如何介导这些操作的模型，但生成和测试 由于缺乏对电路的组织方式缺乏了解，他们的严格预测受到了限制 尊重嗅球肾小球。肾小球代表单个气味受体，因此构成 在此阶段，信息处理的基本单位。 我们的策略是通过首先更好地定义跨越气味“空间”功能图来克服这一差距 背侧嗅球的肾小球。为了实现这一目标，我们将在功能上定义glomeruli 它们具有最大敏感性的气味及其在经过精心挑选的 气味面板，产生背侧嗅球的第一张“气味灵敏度”图，并允许快速和快速 可靠地识别动物各个肾小球的可靠鉴定。我们将使用这些数据发现新的见解 肾小球气味图的组织，并生成公共资源，以进一步探索 神经科学社区。接下来，我们将使用此知识严格测试替代模型 电路通过比较强度响应函数来塑造嗅球的输入输出功能 感官输入和肾小球输出，以及通过从中选择性地删除特定的中间神经元类型 嗅球网络。我们还将测试替代模型，以了解不同的抑制作用 肾小球是有组织的，以及如何使用有选择性的气味来形成它们的气味经验 激活已鉴定的肾小球的不同组合。 我们的实验策略以创新方法为基础，这是实现新水平的关键 了解如何通过嗅球电路转化气味表示。首先，我们能够 反复识别并瞄准在背部嗅球上的许多肾小球 在单个实验中，诊断气味剂并有效地映射了许多气味的响应。第二，我们是 能够从感觉输入到肾小球，投影神经元输出或两者兼而有之 同时，使我们能够通过嗅觉电路精确表征输入输出转换。 最后，我们将开发一个改进的嗅球网络模型，该模型受到高度约束 实验数据以及应该导致对该网络如何改变气味表示和的新见解 启用可以通过进一步的电路操作或行为测定进行测试的新预测。