Milinski Linus, Nodal Fernando R, Vyazovskiy Vladyslav V, Bajo Victoria M
Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford OX1 3PT, UK.
Brain Commun. 2022 Apr 5;4(3):fcac089. doi: 10.1093/braincomms/fcac089. eCollection 2022.
Sensory disconnection from the environment is a hallmark of sleep and is crucial for sleep maintenance. It remains unclear, however, whether internally generated percepts-phantom percepts-may overcome such disconnection and, in turn, how sleep and its effect on sensory processing and brain plasticity may affect the function of the specific neural networks underlying such phenomena. A major hurdle in addressing this relationship is the methodological difficulty to study sensory phantoms, due to their subjective nature and lack of control over the parameters or neural activity underlying that percept. Here, we explore the most prevalent phantom percept, subjective tinnitus-or tinnitus for short-as a model to investigate this. Tinnitus is the permanent perception of a sound with no identifiable corresponding acoustic source. This review offers a novel perspective on the functional interaction between brain activity across the sleep-wake cycle and tinnitus. We discuss characteristic features of brain activity during tinnitus in the awake and the sleeping brain and explore its effect on sleep functions and homeostasis. We ask whether local changes in cortical activity in tinnitus may overcome sensory disconnection and prevent the occurrence of global restorative sleep and, in turn, how accumulating sleep pressure may temporarily alleviate the persistence of a phantom sound. Beyond an acute interaction between sleep and neural activity, we discuss how the effects of sleep on brain plasticity may contribute to aberrant neural circuit activity and promote tinnitus consolidation. Tinnitus represents a unique window into understanding the role of sleep in sensory processing. Clarification of the underlying relationship may offer novel insights into therapeutic interventions in tinnitus management.
与环境的感觉脱节是睡眠的一个标志，对维持睡眠至关重要。然而，尚不清楚内部产生的感知——幻听——是否能克服这种脱节，以及睡眠及其对感觉处理和大脑可塑性的影响如何反过来影响这些现象背后特定神经网络的功能。由于幻听的主观性质以及对其潜在参数或神经活动缺乏控制，研究感觉幻听在方法上存在困难，这是解决这种关系的一个主要障碍。在此，我们将探讨最常见的幻听——主观性耳鸣（简称耳鸣）——作为研究这一问题的模型。耳鸣是对一种没有可识别相应声源的声音的持续感知。这篇综述为睡眠 - 觉醒周期中大脑活动与耳鸣之间的功能相互作用提供了一个新的视角。我们讨论了清醒和睡眠状态下耳鸣期间大脑活动的特征，并探讨其对睡眠功能和内稳态的影响。我们提出疑问，耳鸣时皮层活动的局部变化是否会克服感觉脱节并阻止全面恢复性睡眠的发生，以及累积的睡眠压力如何可能暂时减轻幻听的持续存在。除了睡眠与神经活动之间的急性相互作用，我们还讨论了睡眠对大脑可塑性的影响如何可能导致异常神经回路活动并促进耳鸣巩固。耳鸣是理解睡眠在感觉处理中作用的一个独特窗口。阐明潜在关系可能为耳鸣治疗干预提供新的见解。
