Research Initiation Award: Development and utilization of fluorescent biosensors for dopamine sensing in Caenorhabditis elegans

历史上的黑人学院和大学本科项目（HBCU-UP）通过研究启动奖为历史上的黑人学院和大学的初级和中期职业教师提供支持，他们正在建立新的研究项目或重新指导和重建现有的研究项目。期望该奖项有助于进一步提高教师的研究能力和效率，并改善本国机构的研究和教学。该奖项授予菲斯克大学，为开发能够以高时空分辨率检测多巴胺的工具提供了机会，从而提高了其对神经回路影响的分析程度。利用秀丽隐杆线虫（C. elegans）作为模式生物，遗传编码蛋白质传感器和非遗传编码纳米传感器将被开发、表征，并用于研究认知功能和动物行为的信号机制。该项目还提供了一个培养本科生的机会，从而为下一代科学家做出贡献，他们可以为科学创新，创造力和生产力做出贡献。多巴胺（DA）是一种重要的神经递质，涉及动物王国中许多不同的保守信号功能，包括人类。尽管它在运动控制、奖励动机行为和学习等过程中具有众所周知的重要性，但仍然缺乏追踪DA水平或体内DA神经元活动的工具。本项目旨在开发线虫体内能够精确测量DA时空含量的DA生物传感器。基因编码和合成的DA生物传感器将被开发成含有荧光成分，当DA释放时会发光。突触前囊泡释放DA后，DA与受体结合，导致荧光强度增加。合成的DA纳米传感器包括a)单壁碳纳米管传感器（nIRCat）和b)碳点传感器（CD）。DA与nIRCat结合可提高其荧光强度。此外，CDs将与二氧化锰纳米片（NSs）结合使用。CDs是天然的光致发光材料，可以被MnO2 NSs猝灭。然而，DA可以将MnO2 NSs转化为Mn2+离子，导致光致发光信号的恢复。转基因蠕虫（dLight）的荧光显微镜和合成生物传感器的存在，将使动态跟踪DA在活的动物。这些生物传感器将针对秀丽隐杆线虫进行开发和优化，并对其毒性和效率进行研究。利用DA生物传感器结合光遗传学操作神经元活动，将支持进一步研究DA在单细胞水平上的时空传递。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Historically Black Colleges and Universities Undergraduate Program (HBCU-UP) through Research Initiation Awards provide support for junior and mid-career faculty at Historically Black Colleges and Universities who are building new research programs or redirecting and rebuilding existing research programs. It is expected that the award helps to further the faculty member's research capability and effectiveness and improve research and teaching at the home institution. This award to Fisk University provides an opportunity to develop tools that can detect dopamine with high spatiotemporal resolution, thereby enhancing the extent to which its impact on neural circuitry can be analyzed. Utilizing Caenorhabditis elegans (C. elegans) as a model organism, genetically encoded protein sensors and non-genetically encoded nanosensors will be developed, characterized, and used to investigate signaling mechanisms of cognitive function and animal behavior. This project also provides an opportunity to train undergraduate students, thereby contributing to the next generation of scientists who can contribute to scientific innovation, creativity, and productivity.Dopamine (DA) is an important neurotransmitter involved in many different conserved signaling functions across the animal kingdom, including humans. Despite its well-known importance in processes including motor control, reward-motivated behaviors, and learning, there remains a dearth of tools to tracking DA levels or the activity of DA neurons in vivo. This project aims to develop DA biosensors in C. elegans that can precisely measure the spatiotemporal content of DA. Genetically encoded and synthetic DA biosensors will be developed to contain fluorescent components that will emit light upon the release of DA. After release of DA from presynaptic vesicles, DA will bind to the receptor and result an increase of florescent intensity. The synthetic DA nanosensors include a) single-walled carbon nanotube sensors (nIRCat) and b) carbon dot (CD) sensors. Binding of DA to nIRCat will increase its fluorescent intensity. Moreover, CDs will be used in combination with MnO2 nanosheets (NSs). CDs are naturally photoluminescence and can be quenched by MnO2 NSs. However, DA can transform MnO2 NSs into Mn2+ ions and result in the recovery of the photoluminescent signal. Florescent microscopy of the transgenic worm (dLight) and in the presence of synthetic biosensors, will enable dynamic tracking of DA in the live animal. These biosensors will be developed, optimized for C. elegans and their toxicity and efficiency will be investigated. Utilization of DA biosensors in combination with optogenetic manipulation of neuronal activity will support further inquiry on the spatiotemporal transmission of DA at the single cell level.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.