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

灵长类动物的大脑包含皮层区域，这些区域在高级感觉或行为方面表现出选择性参与， 运营这些区域的功能特化被认为是灵长类特定认知功能的核心。 以及相关的疾病。解读灵长类动物脑区功能特化的起源 然而，这是一项非常具有挑战性的任务，这在很大程度上是由于缺乏合适的实验方法。 工具.为了解决这个问题，我们将开发一种方法来衡量对专门领域的投入活动 从整个大脑，允许在多区域神经回路中的信息流的系统分析 从而产生高级功能。我们的方法将采用一个概念上的新家庭的基因编码 一种名为NOSTIC的成像探针，它将表达NOSTIC的神经元的钙信号传导到 可以使用全脑测量技术动态监测的局部血液动力学信号 比如功能性磁共振成像（fMRI）。当使用逆行转运的病毒载体递送时， NOSTIC可以允许基于fMRI的靶向记录分布的细胞群中的神经活动， 单突触输入到大脑中的任何注射靶点。在我们的初步工作中，我们已经创建了第一代 NOSTIC探针，并用它们来证明啮齿动物的遗传靶向功能成像。目标1， 在这个项目中，我们将采取两个步骤，使这个工具适用于非人类灵长类动物。我们将创造第二个- 新一代NOSTIC显示出针对电路特定功能成像的改进性能，同时还开发了 使用病毒载体，使这些探针的表达在灵长类动物的大脑中被纵向追踪。我们将 还将NOSTIC探针用于掺入腺相关病毒，其提供延长的capa- 与我们目前使用的疱疹病毒相比，在目标2中，我们将进行试点实验， NOSTIC是否可以在非人类灵长类动物中提供电路特异性读数。这些测试已经被... 使用我们目前可用的探针和载体，Aim 1的新变体也将在 available.在绒猴中成功演示NOSTIC电路成像功能， 进入该项目UH 3阶段的拟议通过/不通过标准。然后在目标3（UH 3阶段），我们将 在两种范式中验证NOSTIC探针，探索它们在大脑区域的表现，实验 上下文和灵长类物种。在第一个范例中，我们将应用NOSTIC来检查功能性的起源。 绒猴大脑中面部选择区域的专门化。在第二个范例中，我们将应用NOSTIC 研究猕猴视觉系统腹侧流对物体选择性反应的全脑贡献 皮层这些实验将作为多实验室合作进行，既利用和传播， nate的NOSTIC技术;这项工作将因此建立一个广泛适用的变革方法， 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.