Hemogenetic imaging technology for circuit-specific analysis of primate brain function

灵长类动物的大脑包含有选择性地参与高级感觉或行为的皮质区域 行动。这些区域的功能专门化被认为是灵长类特有认知的核心。 以及与之相关的疾病。破译灵长类脑区功能特化的起源 然而，这是一项极具挑战性的任务，这在很大程度上是由于缺乏合适的实验 工具。为了解决这个问题，我们将开发一种方法来衡量专门领域的投入活动 从整个大脑，允许系统地分析多区域神经回路中的信息流 这就产生了高级别的功能。我们的方法将使用一个概念上新的家族的基因编码 成像探针被称为nostics，它将表达nostic的神经元的钙信号传导到 可使用全脑测量技术动态监测的局部血流动力学信号 比如功能磁共振成像(FMRI)。当使用逆行运输的病毒载体递送时， 病理学家可以基于fMRI对分布式细胞群中的神经活动进行有针对性的记录，从而提供 对大脑中任何注射目标的单突触输入。在前期工作中，我们创造了第一代 NOSTIC探针，并用它们展示了啮齿动物的基因靶向功能成像。在目标1中 在这个项目中，我们将采取两个步骤，使这种工具适用于非人类灵长类动物。我们将创造第二个- 显示特定于电路的功能成像的改进性能的新一代诺斯通，同时还开发了 这种病毒载体允许在灵长类动物的大脑中纵向跟踪这些探针的表达。我们会 还可以使NOSTIC探针与腺相关病毒结合，从而提供更广泛的CapA- 与我们目前使用的疱疹病毒相比，它的效率更高。在目标2中，我们将进行初步实验，以研究 伤害者是否能在非人类灵长类动物中提供电路特异性读数。这些测试已经准备好了- 使用我们目前可用的探针和载体，Aim 1的新变种也将在以下情况下进行测试 可用。成功演示NOSTIC用于绒猴电路成像的功能构成了我们的 为进入本项目的UH3阶段而提出的进入/不通过的标准。然后在目标3(UH3阶段)，我们将 在两个范例中验证NOSTIC探针，以探索其跨大脑区域的性能，实验性 环境和灵长类物种。在第一个范例中，我们将应用注释学来检查泛函的起源 专门研究绒猴大脑的脸部选择区域。在第二个范例中，我们将应用nostics 研究猕猴视觉腹侧流中全脑对物体选择反应的贡献 大脑皮层。这些实验将作为多个实验室合作进行，既利用并传播- Nate NOSTIC技术；因此，这项工作将建立一种广泛适用的转型方法 灵长类动物大脑功能的机制分析。

Primate brains contain cortical areas that exhibit selective engagement in high-level sensory or behavioral operations. The functional specialization of these regions is thought to be central to primate-specific cognitive faculties and to associated disorders. Deciphering the origins of functional specialization in primate brain regions has been an enormously challenging task, however, due in large part to the absence of suitable experimental tools. To address this problem, we will develop a method for measuring the activity of inputs to specialized areas from throughout the brain, permitting systematic analyses of information flow in the multiregional neural circuitry that gives rise to high-level functions. Our method will employ a conceptually new family of genetically encoded imaging probes called NOSTICs, which transduce the calcium signaling of NOSTIC-expressing neurons into localized hemodynamic signals that can be dynamically monitored using brain-wide measurement techniques like functional magnetic resonance imaging (fMRI). When delivered using retrogradely transported viral vectors, NOSTICs can permit targeted fMRI-based recording of neural activity in distributed cell populations that provide monosynaptic input to any injection target in the brain. In our preliminary work, we have created first-generation NOSTIC probes and used them to demonstrate genetically targeted functional imaging in rodents. In Aim 1 of this project, we will take two steps that adapt this tool for use in nonhuman primates. We will create second- generation NOSTICs that display improved performance for circuit-specific functional imaging, while also devel- oping viral vectors that allow expression of these probes to be tracked longitudinally in primate brains. We will also adapt the NOSTIC probes for incorporating into adeno-associated viruses, which provide extended capa- bility compared with the herpes viruses we currently use. In Aim 2, we will perform pilot experiments to investigate whether NOSTICs can provide circuit-specific readouts in nonhuman primates. These tests will already be pos- sible using our currently available probes and vectors, and new variants from Aim 1 will also be tested when available. Successful demonstration of NOSTIC functionality for circuit imaging in marmosets constitutes our proposed go/no-go criterion for entry into the UH3 stage of this project. Then in Aim 3 (UH3 stage), we will validate NOSTIC probes in two paradigms that explore their performance across brain regions, experimental contexts, and primate species. In the first paradigm, we will apply NOSTICs to examine origins of functional specialization in face-selective regions of the marmoset brain. In the second paradigm, we will apply NOSTICs to investigate brain-wide contributions to object selective responses in the ventral stream of the macaque visual cortex. These experiments will be performed as multi-laboratory collaborations that both harness and dissemi- nate the NOSTIC technology; this work will therefore establish a broadly applicable transformative approach for mechanistic analysis of primate brain function.