Effects of environmental thyroid hormone disrupting compounds on CNS development

描述(由申请人提供) 这位候选人的长期目标是成为一家学术研究机构的独立研究员，研究激素和内分泌干扰化合物对大脑回路发育和活动的影响。他在神经内分泌学、神经可塑性和行为神经科学方面接受过出色的培训。他现在计划通过培训补充这些知识和技术专长，通过电穿孔、延时双光子成像、神经元重建和结构分析、电生理学和甲状腺激素水平的量化，通过有针对性地操纵基因表达，在体内分析内分泌干扰物对神经元结构可塑性和大脑电路连接的作用。在此培训期间，应聘者将参加课程和研讨会，以提高其管理能力、沟通技能和技术素养。到这个奖项结束时，他将获得建立自己的实验室所需的技能和培训。他还将拥有出版记录和手头的初步数据，以撰写一份极有可能获得资金的R01提案。 指导阶段的大部分培训将在斯克里普斯研究所(TSRI)进行，由霍利斯·克莱恩博士监督。克莱恩博士采用多学科方法研究非洲爪哇蝌蚪视觉系统发育的分子和细胞机制，包括活体时间推移双光子成像、视觉反应的在体电生理记录、钙成像和行为。她的实验室一直处于开发令人兴奋的新技术的前沿，以研究调节电路发展的因素。她的实验室位于多里斯神经科学中心，这是一个杰出的智力环境，由14名教职员工和100多名博士后和其他科学家组成。候选人提出的一些实验将受益于共同导师Ardem Patapoutian博士的培训，他是TSRI的教职员工，在TRPA1通道的生物物理学方面拥有专业知识，候选人将使用该通道来操纵神经元活动。此外，候选人还将在密歇根大学安娜堡分校罗伯特·丹佛博士的实验室学习测量甲状腺激素水平的技术。丹佛博士是内分泌干扰和生理学方面的领先专家，将是该项目的宝贵合作导师。 这项研究项目的目标是确定内分泌干扰化合物对大脑发育的影响。工业和消费品生产中使用的化合物可以在环境中积累，甚至可以在人体血液和组织中发现可测量的数量。越来越多的证据表明，其中一些化合物可以影响激素代谢和行动，包括对大脑发育起重要作用的甲状腺激素。然而，人们对扰乱甲状腺激素功能的环境毒素如何影响大脑回路的发育知之甚少。候选人将利用非洲爪哇蝌蚪的视觉系统来确定甲状腺激素干扰化合物对中枢神经系统发育的影响，这是进行这些研究的理想实验系统，因为动物的外部发育为观察和操作发育中的大脑提供了容易的途径。候选人将用活性甲状腺激素三碘甲腺原氨酸、他巴唑(一种甲状腺激素拮抗剂)和几种甲状腺激素干扰化合物来治疗蝌蚪。我将评估大脑发育的几个参数，包括神经干细胞的增殖、分化和存活，以及神经元结构和电路连接的发展。此外，他将开发和表征微球作为局部甲状腺激素输送系统的使用，并使用该系统针对视网膜或视顶盖进行特定的激素治疗。这些实验将使他能够消除发育中大脑中激素作用部位的歧义，并定位甲状腺激素干扰化合物对大脑发育的作用部位和影响。这将是环境毒理学、神经内分泌学和脑发育领域的重要进展。此外，这些实验将建立非洲爪哇视网膜顶盖系统，作为筛选甲状腺激素干扰化合物对大脑发育影响的理想模型。

DESCRIPTION (provided by applicant) The candidate's long term goal is to become an independent investigator at an academic research institution to study the effects of hormones and endocrine disrupting compounds on the development and activity of brain circuits. He has received excellent training in neuroendocrinology, neuroplasticity, and behavioral neuroscience. He now plans to complement this knowledge and technical expertise with training in in vivo analysis of the role of endocrine disruptors on neuronal structural plasticity and brain circuit connectivity using targeted manipulation of gene expression via electroporation, time-lapse 2-photon imaging, neuronal reconstruction and structural analysis, electrophysiology and quantification of thyroid hormone levels. During this training period the candidate will enroll in courses and seminars to improve his management abilities, communication skills and technical literacy. By the end of this award, he will have gained the skills and training that will be needed for establishing his own lab. He wil also have the publication record and preliminary data on hand to write a R01 proposal with a high likelihood of funding. Most of the training during the mentored phase will occur at The Scripps Research Institute (TSRI) under the supervision of Dr. Hollis Cline. Dr. Cline has taken a multidisciplinary approach to studying molecular and cellular mechanisms that govern the development of the visual system in Xenopus laevis tadpoles, including in vivo time-lapse 2 photon imaging, in vivo electrophysiological recordings of visual responses, calcium-imaging and behavior. Her laboratory has been at the forefront of developing exciting new techniques to study the factors that regulate circuit development. Her laboratory is located in the Dorris Neuroscience Center, which is an outstanding intellectual environment consisting of 14 faculty members and more than 100 postdocs and other scientists. Some of the candidate's proposed experiments will benefit from training from a co-mentor, Dr. Ardem Patapoutian, a TSRI faculty member with expertise in biophysics of the TRPA1 channels, which the candidate will use to manipulate neuronal activity. In addition, the candidate will learn techniques to measure thyroid hormone levels in the laboratory of Dr. Robert Denver at the University of Michigan at Ann Arbor. Dr. Denver is a leading expert in endocrine disruption and physiology and will be an invaluable co-mentor to this project. The goal of this research project is determine the effects of endocrine-disrupting compounds on brain development. Compounds that are used in the production of industrial and consumer products can accumulate in the environment and even be found in human blood and tissue in measurable quantities. There is increasing evidence that some of these compounds can affect hormone metabolism and action, including thyroid hormone, which plays an important role in brain development. Yet little is known about how environmental toxins that disrupt thyroid hormone function affect development of brain circuits. The candidate will determine the effects of thyroid hormone disrupting compounds on CNS development, using the visual system in Xenopus laevis tadpoles, an ideal experimental system for these studies because the external development of the animal provides easy access to the developing brains for observation and manipulation. The candidate will treat tadpoles with the active thyroid hormone triiodothyronine, methimazole (a thyroid hormone antagonist), and several thyroid hormone disrupting compounds. I will assess several parameters of brain development, including neural stem cell proliferation, differentiation and survival, and the development of neuronal structure and circuit connectivity. In addition, he will develop and characterize the use of microspheres as a local thyroid hormone delivery system and use this system to target particular hormone treatments to the retina or the optic tectum. These experiments will allow him to disambiguate the site of hormone action within the developing brain and to localize the sites of action and effects of thyroid hormone disrupting compounds on brain development. These will be important advances in the fields of environmental toxicology, neuroendocrinology and brain development. Furthermore, these experiments will establish the Xenopus retino-tectal system as an ideal model to screen thyroid hormone disrupting compounds for effects on brain development.