Vicencio-Jimenez Sergio, Bucci-Mansilla Giuliana, Bowen Macarena, Terreros Gonzalo, Morales-Zepeda David, Robles Luis, Délano Paul H
Departamento de Otorrinolaringología, Hospital Clínico de la Universidad de Chile, Santiago, Chile.
Department of Otolaryngology-Head and Neck Surgery, The Center for Hearing and Balance, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Front Neurosci. 2021 Dec 9;15:759219. doi: 10.3389/fnins.2021.759219. eCollection 2021.
The ability to perceive the world is not merely a passive process but depends on sensorimotor loops and interactions that guide and actively bias our sensory systems. Understanding which and how cognitive processes participate in this active sensing is still an open question. In this context, the auditory system presents itself as an attractive model for this purpose as it features an efferent control network that projects from the cortex to subcortical nuclei and even to the sensory epithelium itself. This efferent system can regulate the cochlear amplifier sensitivity through medial olivocochlear (MOC) neurons located in the brainstem. The ability to suppress irrelevant sounds during selective attention to visual stimuli is one of the functions that have been attributed to this system. MOC neurons are also directly activated by sounds through a brainstem reflex circuit, a response linked to the ability to suppress auditory stimuli during visual attention. Human studies have suggested that MOC neurons are also recruited by other cognitive functions, such as working memory and predictability. The aim of this research was to explore whether cognitive processes related to delayed responses in a visual discrimination task were associated with MOC function. In this behavioral condition, chinchillas held their responses for more than 2.5 s after visual stimulus offset, with and without auditory distractors, and the accuracy of these responses was correlated with the magnitude of the MOC reflex. We found that the animals' performance decreased in presence of auditory distractors and that the results observed in MOC reflex could predict this performance. The individual MOC strength correlated with behavioral performance during delayed responses with auditory distractors, but not without them. These results in chinchillas, suggest that MOC neurons are also recruited by other cognitive functions, such as working memory.
感知世界的能力并非仅仅是一个被动过程，而是依赖于感觉运动环路以及引导并积极影响我们感觉系统的相互作用。了解哪些认知过程以及如何参与这种主动感知仍是一个悬而未决的问题。在这种背景下，听觉系统因其具有从皮层投射到皮层下核团甚至感觉上皮本身的传出控制网络，而成为实现这一目的的一个有吸引力的模型。这个传出系统可以通过位于脑干的内侧橄榄耳蜗（MOC）神经元调节耳蜗放大器的敏感性。在对视觉刺激进行选择性注意时抑制无关声音的能力是归因于该系统的功能之一。MOC神经元也通过脑干反射回路被声音直接激活，这种反应与在视觉注意期间抑制听觉刺激的能力有关。人体研究表明，MOC神经元也会被其他认知功能所激活，如工作记忆和可预测性。本研究的目的是探讨在视觉辨别任务中与延迟反应相关的认知过程是否与MOC功能有关。在这种行为条件下，无论有无听觉干扰物，龙猫在视觉刺激消失后都会延迟超过2.5秒做出反应，并且这些反应的准确性与MOC反射的强度相关。我们发现，在有听觉干扰物的情况下，动物的表现会下降，并且在MOC反射中观察到的结果可以预测这种表现。个体MOC强度与有听觉干扰物时延迟反应期间的行为表现相关，但在没有听觉干扰物时则不然。龙猫的这些结果表明，MOC神经元也会被其他认知功能所激活，如工作记忆。
