Development of in vivo NMR techniques for studying the impact of Ocean acidification and warming on the neurophysiology of Antartic fishes

开发体内核磁共振技术来研究海洋酸化和变暖对南极鱼类神经生理学的影响

基本信息

批准号：
237813768
负责人：
Dr. Christian Bock
金额：
--
依托单位：
Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/237813768?language=en
关键词：
Development vivo NMR techniques studying

项目摘要

The most dramatic effects of ocean acidification and warming are expected in Polar regions, i.e., the impact of elevated temperatures and CO2 concentrations will be highest on Polar organisms (Antarctic and Arctic species). It was demonstrated that tropical fishes show neurological impairments under elevated CO2 concentrations expected from climate change scenarios for 2100 already, although fishes have a decent acid-base regulation. The impairments involved different neurological dysfunctions from sensory to behavioural changes and were supposed to be due to the influence of CO2 on the neurotransmitter function of GABA. Global warming might amplify these disturbances. Thus, in Antarctic eelpout it was shown that acid-base regulation of intracellular pH became impaired at temperatures above 4°C.Polar fishes can show similar or more severe neurological changes under conditions of ocean acidification and warming. However, the mechanisms responsible for the observed disturbances of marine fishes are still not understood. In vivo NMR techniques, in particular localised 31P and 1H NMR spectroscopy were extensively used to characterise the metabolic status or metabolic changes in the brain of animals and humans, including observations on changes of neurotransmitters as well as acid-base regulation. However, these measurements are limited by the inherently low sensitivity, restricting the spatial and temporal resolution.In the current research project, the prolongation of which we are applying for, we exploit the novel approach of chemical shift saturation transfer (CEST) for pH mapping and indirect metabolic imaging. CEST magnetic resonance imaging (MRI) allows measurements with high spatial and temporal resolution because the saturated longitudinal magnetisation of exchangeable protons of metabolites is transferred to water and accumulated. We have shown that CEST MRI is feasible down to polar temperatures and that the specificity of CEST MRI can be adjusted by appropriate radiofrequency (RF) pre-saturation, allowing both inverse imaging of important metabolites and pH mapping. Besides CEST MRI based on glutamate (GluCEST), we plan to develop CEST MRI based on taurine (TauCEST). TauCEST will be a novel CEST option, which seems to be applicable at low temperatures. Using the new 9.4T NMR imaging system, which is expected to be operational in January, 2016, at the AWI, will allow in vivo measurements with improved quality. Both CEST MRI and localized 1H and 31P MRS will be used for studying metabolic changes and acid-base regulation in the brain of Antarctic fishes under expected ocean acidification and warming scenarios. These studies should improve our understanding of the mechanisms underlying the observed neurological changes in Polar fishes.

海洋酸化和变暖的最显着影响是极地区域的，即，温度升高和二氧化碳浓度的影响最高，对极性生物（南极和北极物种）。事实证明，热带鱼类在气候变化情景中预期的2100种二氧化碳浓度升高，尽管鱼类具有良好的酸碱调节，但神经系统损害已经降低。这些障碍涉及从感觉变化到行为变化的不同神经系统功能障碍，预计是由于CO2对GABA神经递质功能的影响。全球变暖可能会放大这些灾难。在南极浮游物中，表明细胞内pH的酸碱调节在高于4°的温度下受到损害。在海洋酸化和变暖的条件下，极性鱼类会显示出相似或更严重的神经系统变化。但是，仍然尚不清楚导致海洋鱼类障碍的机制。体内NMR技术，特别是局部局部31p和1H NMR光谱法广泛地用于表征动物和人类大脑中的代谢状态或代谢变化，包括观察神经递质的变化以及酸碱酶调节的变化。但是，这些测量值受到固有低灵敏度的限制，限制了空间和临时分辨率。在当前的研究项目中，我们申请的延长，我们利用了用于pH映射和间接代谢成像的新型化学移位满意度转移方法（CEST）的新方法。 CEST磁共振成像（MRI）允许以高空间和临时分辨率进行测量，因为将代谢物的可交换质子的饱和纵向磁化转移到水中并积累。我们已经表明，CEST MRI可行至极性温度，并且可以通过适当的辐射射频（RF）预饱和度调节CEST MRI的特异性，从而允许对重要代谢物和pH映射进行反向成像。除了基于谷氨酸（Glucest）的CEST MRI外，我们计划基于牛磺酸（Taucest）开发CEST MRI。 Taucest将是一种新颖的CEST选择，它似乎适用于低温。使用新的9.4T NMR成像系统，预计将于2016年1月在AWI上运行，将允许质量提高的体内测量。在预期的海洋酸化和变暖的情况下，CEST MRI和局部MRS MRS将用于研究南极鱼大脑中的代谢变化和酸碱调节。这些研究应提高我们对观察到的极性鱼类神经系统变化的机制的理解。