Functional MRS at 7T to Study Neuronal Inhibition in Humans

描述（由申请人提供）：表征工作人脑中神经元放电抑制的潜在代谢/神经化学事件是一项具有挑战性的任务。质子磁共振波谱（MRS）允许无创测量人脑中的代谢物浓度。然而，质子MRS的低灵敏度会限制该方法检测代谢物浓度的微小变化的可靠性和准确性，尤其是那些以低浓度存在的代谢物，例如葡萄糖、乳酸盐或g-氨基丁酸（GABA）。这些限制损害了对神经元过程的强有力研究，这些过程会产生大脑神经化学特征的微妙变化，例如神经元放电抑制。在这个项目中，我们将受益于增加的灵敏度 由7 T扫描仪提供，能够可靠和准确地检测脑神经化学谱的变化，这对表征神经元放电抑制至关重要。通过在7 T下进行功能MRS的研究，我们在过去已经获得了在初级视皮层中神经元活动增加的功能范例期间多种代谢物变化的稳健结果。这些结果被证明对了解生理条件下的脑代谢非常有帮助。在本项目中，我们将扩展这项技术，以进一步解决神经元抑制的代谢/神经化学底物。测量抑制性（GABA）和兴奋性（谷氨酸）神经递质以及大脑燃料（主要是葡萄糖和乳酸）的机会对于全面了解抑制的代谢/神经化学相关性至关重要。这项研究将提供新的实验证据，以帮助理解人类大脑中的神经元抑制，这不仅对我们对整体大脑功能的基本理解很重要，而且对理解和监测许多大脑疾病，如精神分裂症，癫痫或帕金森病也很重要。

DESCRIPTION (provided by applicant): The characterization of the underlying metabolic/neurochemical events of neuronal firing suppression in the working human brain is a challenging task. Proton magnetic resonance spectroscopy (MRS) allows the non- invasive measurement of metabolite concentrations in the human brain. However, the low sensitivity of proton MRS can limit the reliability and accuracy of the method to detect small variations in the concentration of metabolites, especially of those present in low concentration, such as glucose, lactate or g-aminobutyric acid (GABA). These limitations impair a robust investigation of neuronal processes which produce subtle changes in the neurochemical profile of the brain, such as neuronal firing suppression. In this project we will benefit from the increased sensitivity offered by 7T scanners to enable the reliable and accurate detection of changes in the brain neurochemical profile which are critical to characterize neuronal firing suppression. By conducting studies of functional MRS at 7T, we have in the past obtained robust results of multiple metabolite changes during functional paradigms of increased neuronal activity in the primary visual cortex. These results were proven to be extremely helpful to understand brain metabolism in physiological conditions. With the present project, we will extend this technology to further address the metabolic / neurochemical substrates of neuronal inhibition. The opportunity to measure inhibitory (GABA) and excitatory (glutamate) neurotransmitters, as well as the fuels of the brain (mainly glucose and lactate), is critical to gain comprehensive insight into the metabolic/neurochemical correlates of inhibition. This research will provide new experimental evidence to help understand neuronal inhibition in the human brain, which is important not only for our basic understanding of overall brain function, but also for the understanding and monitoring of many brain disorders such as schizophrenia, epilepsy or Parkinson's disease.