Optogenetic tools to distinguish neuronal class in behaving non-human primates

描述（由申请人提供）：理解行为背后的神经机制的一个主要障碍是我们无法区分记录中的神经元类别和行为动物。小鼠转基因系，包括CRE系，已经使得可以使用光遗传学技术来选择性地激活不同的类别以确定它们的功能。 行为中的角色。然而，基于光遗传学刺激确定神经元身份仍然是一个挑战，因为对直接刺激的响应的潜伏期可能与强烈但间接的双突触兴奋重叠。拟议的研究将引入新的方法来区分直接和间接刺激，以标记神经元的身份。将进一步发展这些方法，用于线阵电极的细胞外记录，并使用电流源密度（CSD）分析来确定层流位置。这些方法将在CRE小鼠中验证，然后应用于绒猴（Callithrix jacchus）。绒猴是一个特别有趣的灵长类动物模型，因为它提供了解剖神经回路的机会，可以与小鼠相媲美。它成熟迅速，在人工饲养中繁殖良好，因此它适合用于小鼠的遗传操作，并产生了第一个灵长类转基因品系。它也有一个平的皮质，有助于层状记录。初步数据显示，绒猴可以在头部约束下执行视觉任务，使它们适合清醒的神经生理学。建立这些方法将为在机械水平上研究皮层回路创造机会，使该领域能够理解皮层回路中的畸变如何引起破坏性疾病，如精神分裂症和自闭症。

DESCRIPTION (provided by applicant): A major obstacle to understanding the neural mechanisms underlying behavior is our inability to distinguish between neuronal classes in recordings from behaving animals. Mouse transgenic lines, including CRE lines, have made it possible to use optogenetic techniques to selectively activate different classes to determine their role in behavior. However, it remains a challenge to determine the neuronal identity based on optogenetic stimulation, as the latency of response to direct stimulation can overlap with strong but indirect disynaptic excitation. The proposed research will introduce novel methods for distinguishing direct from indirect stimulation in order to label neuronal identity. It will furthe develop these methods for extracellular recordings made with linear array electrodes and using current source density (CSD) analysis to identify laminar location. These methods will be validated in CRE mice, and then applied to the marmoset (Callithrix jacchus). The marmoset is a particularly interesting primate model because it offers opportunities for dissecting neural circuitry that are comparable to the mouse. It matures quickly and breeds well in captivity, so it is amenable to the kinds of genetic manipulation used in mice and has produced the first primate transgenic lines. It also has a lissencephalic (flat) cortex which aids in laminar recordings. Preliminary data show marmosets can perform visual tasks under head-restraint, making them suitable to awake neurophysiology. Establishing these methods will create opportunities to study cortical circuits at a mechanistic level, enabling the field to understand how aberrations in the cortical circuitry give rise to devastating disorders such as schizophrenia and autism.