"Mechanisms underlying nicotine induced neuronal toxicity in zebrafish"

描述（由申请人提供）：胚胎暴露于尼古丁对人类发育有不同程度的有害影响。这种暴露会导致与学习和记忆有关的认知能力和行为的长期变化。许多哺乳动物模型被用来理解尼古丁是如何产生这种影响的，但这很困难，因为大多数哺乳动物的行为及其背后的神经系统都很复杂。我们正在研究尼古丁对模型脊椎动物斑马鱼的影响，目的是将尼古丁暴露造成的行为异常与脊髓神经元和相关脊髓肌肉组织的发育改变联系起来。斑马鱼胚胎对尼古丁暴露敏感（Svoboda等人，2002年）。剧烈暴露于尼古丁的胚胎在通常不游泳的时候表现出类似游泳的行为。另一方面，长期让胚胎接触尼古丁会导致瘫痪。这两种行为表型为我们指明了斑马鱼胚胎期尼古丁暴露可能改变的候选细胞类型。在本提案中，胚胎尼古丁暴露对脊髓神经元和相关肌肉组织的影响将被确定。据我们所知，这是第一次尝试利用斑马鱼模型来了解胚胎尼古丁暴露的后果。目的是：1)系统地识别和表征所有的斑马鱼nachr， 2)在机制水平上确定尼古丁暴露对运动神经元和肌肉发育的影响，3)在机制水平上确定尼古丁暴露对胚胎感觉神经元发育的影响，4)确定胚胎短暂尼古丁暴露产生的表型是否持续到成年。这些目标中的每一个都解决了一个基本问题，即外源尼古丁如何在脊椎动物发育过程中潜在地发挥其影响。首先，他们描述了早期胚胎暴露于尼古丁导致的行为和神经解剖学表型。其次，它们提供了这些表型如何产生的机制见解。这项工作是发育神经毒理学的基础研究。它为斑马鱼在体内的应用奠定了基础，从而揭示了发育过程中尼古丁暴露影响的机制。

DESCRIPTION (provided by applicant): Embryonic exposure to nicotine has deleterious consequences on human development at various levels. Such exposure can lead to long term changes in the cognitive abilities and behaviors related to learning and memory. Many mammalian models have been employed to understand how nicotine can exert such effects, but this is difficult because most mammalian behaviors and the nervous system underlying them are complex. We are studying the effects of nicotine exposure in a model vertebrate, the zebrafish, with the goal of linking behavioral abnormalities created by nicotine exposure to developmental alterations in spinal neurons and associated spinal musculature. Zebrafish embryos are sensitive to nicotine exposure (Svoboda et. al, 2002). Embryos acutely exposed to nicotine exhibit a swimming-like behavior at time when they typically do not swim. On the other hand, chronically exposing embryos to nicotine, results in paralysis. These two behavioral phenotypes point us toward candidate cell types that may be altered in zebrafish by embryonic nicotine exposure. In this proposal the consequences of embryonic nicotine exposure on spinal neurons and associated musculature will be determined. To our knowledge, this is the first attempt at utilizing the zebrafish model to understand the consequences of embryonic nicotine exposure. The aims are: 1) To systematically identify and characterize all of the zebrafish nAChRs, 2) to determine the consequences of nicotine exposure on motoneuron and muscle development at the mechanistic level, 3) to determine the consequences of nicotine exposure on embryonic sensory neuron development at the mechanistic level, 4) To determine if phenotypes that arise form transient embryonic nicotine exposure persist into adulthood. Each of these aims addresses a fundamental issue relating to how exogenous nicotine potentially exerts its effects during vertebrate development. First, they describe behavioral and neuroanatomical phenotypes that result from early embryonic exposure to nicotine. Secondly, they provide mechanistic insight into how those phenotypes could arise. The work is basic research in developmental neurotoxicology. It serves to establish a foundation whereby zebrafish can be utilized in vivo to unravel the mechanisms that underlie the effects of nicotine exposure during development.