Development of a New Strategy for Treatment of Tonal Tinnitus Based on Lateral Inhibition and Plasticity of the Human Auditory Cortex

过去几年的神经科学研究支持这样的观点，即耳鸣是一种神经再生现象，当部分听力损失导致听觉皮质失去正常输入时，耳鸣就会发展起来。三种不同的神经科学和电生理因素似乎在这一观点中扮演着特殊的角色：神经可塑性、皮质重塑和侧向抑制。最近有迹象表明，通过适当设计的行为训练程序，可以重塑人类的听觉皮质，并有可能通过脑磁图来测量这些变化。所获得的结果指出，有可能利用在正常听力受试者中研究人类神经可塑性所获得的知识来设计训练程序，该训练程序可能部分逆转导致耳鸣的皮质变化，或者防止这些变化在个人身上发生，因为个人有因部分听力丧失而有耳鸣的风险。在这个研究项目中，我们计划进行两个系列的实验工作。在第一章中，我们将通过对掩蔽和测试信号的一系列定量操作来进一步研究听觉侧向抑制的基本机制。这些洞察力有望获得，不仅可以更好地了解听觉系统中央部分的侧向抑制，而这些侧向抑制还没有得到充分的研究，而且还可以为实验的第二部分准备最好的耳鸣掩蔽器设计。新开发的耳鸣治疗方法主要基于侧向抑制和皮质重塑的影响，然后将在一组患有强直性耳鸣的患者中进行双盲试验设计，并结合改进的临床耳鸣测试组进行测试。耳鸣组的临床和心理声学结果将与全头脑磁图进行的神经生理测量的定量结果相关联。

Neuroscience research over the last several years supports the view that tinnitus is a neuroplastic phenomenon which develops, when the auditory cortex is deprived of its normal input by partial hearing loss. Three different neuroscientific and electrophysiological factors seem to play a particular role in this view: neuroplasticity, cortical remodeling and lateral inhibition. Recently there were indications that the human auditory cortex can be remodeled with suitably designed behavioral training procedures, and that it is possible to measure these changes by means of magnetoencephalography. Obtained results are pointing out that it would be possible to use the knowledge gained from the studies of human neural plasticity in normal hearing subjects to design training procedures that may partly reverse the cortical changes that lead to tinnitus, or prevent these changes from occurring in individuals, who are at risk for tinnitus owing to partial hearing loss. In this research project we are planning two series of experimental work. In the first one we will further investigate the basic mechanisms of auditory lateral inhibition by series of quantitative manipulations of the masking and testing signals. The insights, which are expected to be gained, will allow not only to better understand the lateral inhibition in the central part of the auditory system that is insufficiently investigated, but also to prepare the best possible tinnitus masker design for the second part of the experiments. The newly developed approach for tinnitus management, based mainly on the effects of lateral inhibition and cortical remodeling, will then be tested in a population of patients with tonal tinnitus in a double-blinded experimental design in conjunction with a modified clinical tinnitus test battery. The clinical and the psycho-acoustic results obtained in the tinnitus group will be correlated with the quantitative results of neurophysiological measurements performed by whole head magnetoencephalography.