Electrosensory Processing of Plankton Capture in the Paddlefish Brain

这项拟议中的研究将增加对脊椎动物大脑如何处理感官信息并将其转化为适当行为的理解。 一种非常独特的动物和感觉机制是该项目的主题，即美国白鲟，它通过感知微小水蚤发出的微弱电信号来探测和捕获其捕食者。成功进食不需要其他感觉方式。 极小的电场被皮肤感受器检测到，并传递到大脑的后部（原始）区域，在那里它们被处理并发送到中脑，在那里产生控制游泳和进食的运动命令。 这项研究将建立在已知的关于白鲟大脑如何根据后脑神经细胞的生理反应特性及其投射到中脑的解剖学特征来解释电信号的基础上。 将染料微注射到大脑中，这些染料沿着细胞的轴突和树突运输，这些形态特征构成了大脑的接线图。 插入大脑的微电极允许记录单个神经元对感官刺激的反应的动作电位或尖峰活动。 使用这些实验程序，研究的当前阶段将集中在中脑细胞如何从电感觉和视觉输入中收集信息，单个细胞如何代表外部环境的复杂特征，以及这些细胞投射到后脑和脊髓的各种处理中心（脑核），激活肌肉触发行为反应。 这项研究已经对理解电信号在白鲟生物学和相应的保护工作中的作用产生了重大影响，而人类并没有经历过这种作用。 这项研究也有助于高中、大学和研究生院学生的研究教育和培训。

The proposed research will increase understanding of how the vertebrate brain processes sensory information and translates it into appropriate behaviors. A very unique animal and sensory mechanism is the subject of the project, the American paddlefish, which detects and captures its planktonic prey by sensing the weak electric signals from tiny water fleas. No other sensory modalities are necessary for successful feeding. The extremely small electric fields are detected by skin receptors and relayed to the posterior (primitive) region of the brain where they are processed and sent forward to the midbrain where motor commands are generated that govern swimming and feeding. This research will build on what is already known about how the paddlefish brain interprets electrical signals in terms of the physiological response properties of nerve cells in the hindbrain and their anatomical features in projecting to the midbrain. Dyes are microinjected into the brain that are transported along axons and dendrites of the cells, morphological features that constitute the wiring diagrams of the brain. Microelectrodes inserted into the brain allow the action potentials or spike activity of individual neurons to be recorded in response to sensory stimuli. Using these experimental procedures the current phase of the study will focus on how cells in the midbrain collect information from electrosensory and visual inputs, how individual cells come to represent complex features of the external environment, and the projection of these cells into the various processing centers (brain nuclei) of the hindbrain and spinal cord that activate the muscles triggering behavioral responses. This research has already had a significant impact on understanding the role of electrical signals, which humans do not experience, in paddlefish biology and corresponding conservation efforts. The study has also contributed to the research education and training of students in high school, college, and graduate school.