Integration of Ectopic Neurons into Motor Circuits

动物的行为是由大脑和脊髓中相互连接的神经细胞回路驱动的。尽管这些网络在进化史上的多样化导致了我们今天在动物身上观察到的令人难以置信的行为范围，但很少有人做过工作来解决这个基本问题：神经回路是如何进化的？神经回路可能发生变化的一种方式是通过向大脑添加新的神经细胞，并随后将它们整合到功能网络中。这项研究利用鱼的惊吓神经回路来探索在回路中添加新神经细胞的效果。惊吓回路有利于作为研究改变回路机制的案例研究，因为它包含相对较少且容易识别的神经细胞，并控制离散且描述良好的行为。新的惊吓神经元将被遗传地引入后脑。生理记录和激光消融技术将用于检查特定细胞在动物体内的作用。年代的行为。据推测，当新的神经细胞与先前存在的电路建立一些连接时，其他连接将受到限制，并且电路中功能的冗余可能会掩盖异常的神经细胞活动，防止其破坏行为。通过研究新的神经细胞如何整合到大脑中简单的神经回路中，这项研究将为理解回路可能通过进化被修改的原理和洞察这种变化的灵活性和限制提供一个案例研究。该提案的广泛影响包括通过学校和研究实验室的活动向芝加哥南部弱势地区的中学女生伸出援手。此外，这项拟议的研究将涉及本科生和研究生，为各种科学方法和方法的培训提供机会。

Animal behavior is driven by interconnected circuits of nerve cells in the brain and the spinal cord. Although diversification of these networks through evolutionary history has led to the incredible range of behaviors we observe in animals today, little work has been done to address the fundamental question: How do neural circuits evolve? One way in which neural circuits may change is through the addition of new nerve cells to the brain and their subsequent incorporation into functional networks. This research uses the startle neural circuit of fish to explore the effects of adding new nerve cells to circuits. The startle circuit is advantageous to use as a case study for examining mechanisms for changing circuits because it includes relatively few and easily identified nerve cells and controls a discrete and well-described behavior. New startle neurons will be genetically introduced into the hindbrain. Physiological recordings and laser ablation techniques will be used to examine the role specific cells play in the animal?s behavior. It is hypothesized that while new nerve cells make some connections into preexisting circuits other connections will be restricted and that redundancy of function within circuits may act to mask aberrant nerve cell activity, preventing it from disrupting behaviors. By investigating how new nerve cells integrate into simple neural circuits in the brain, this research will provide a case study for understanding principles by which circuits may be modified through evolution and insight into the flexibility for and constraints on such changes. The broader impact of this proposal includes outreach to middle school girls in disadvantaged areas of the south side of Chicago through activities in schools and in the research laboratory. In addition, this proposed research will involve undergraduates and graduate students, providing opportunities for training in a diverse array of scientific approaches and methodologies.