Adibi Mehdi, Lampl Ilan
Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
Department of Neuroscience and Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
Front Neurosci. 2021 Oct 29;15:770011. doi: 10.3389/fnins.2021.770011. eCollection 2021.
In the natural environment, organisms are constantly exposed to a continuous stream of sensory input. The dynamics of sensory input changes with organism's behaviour and environmental context. The contextual variations may induce >100-fold change in the parameters of the stimulation that an animal experiences. Thus, it is vital for the organism to adapt to the new diet of stimulation. The response properties of neurons, in turn, dynamically adjust to the prevailing properties of sensory stimulation, a process known as "neuronal adaptation." Neuronal adaptation is a ubiquitous phenomenon across all sensory modalities and occurs at different stages of processing from periphery to cortex. In spite of the wealth of research on contextual modulation and neuronal adaptation in visual and auditory systems, the neuronal and computational basis of sensory adaptation in somatosensory system is less understood. Here, we summarise the recent finding and views about the neuronal adaptation in the rodent whisker-mediated tactile system and further summarise the functional effect of neuronal adaptation on the response dynamics and encoding efficiency of neurons at single cell and population levels along the whisker-mediated touch system in rodents. Based on direct and indirect pieces of evidence presented here, we suggest sensory adaptation provides context-dependent functional mechanisms for noise reduction in sensory processing, salience processing and deviant stimulus detection, shift between integration and coincidence detection, band-pass frequency filtering, adjusting neuronal receptive fields, enhancing neural coding and improving discriminability around adapting stimuli, energy conservation, and disambiguating encoding of principal features of tactile stimuli.
在自然环境中,生物体不断受到持续的感觉输入流的影响。感觉输入的动态变化随生物体的行为和环境背景而变化。上下文的变化可能会使动物所经历的刺激参数发生超过100倍的变化。因此,生物体适应新的刺激“饮食”至关重要。反过来,神经元的反应特性会动态地调整以适应感觉刺激的主要特性,这一过程称为“神经元适应”。神经元适应是所有感觉模态中普遍存在的现象,并且发生在从外周到皮层的不同处理阶段。尽管对视觉和听觉系统中的上下文调制和神经元适应进行了大量研究,但对体感系统中感觉适应的神经元和计算基础了解较少。在这里,我们总结了关于啮齿动物胡须介导的触觉系统中神经元适应的最新发现和观点,并进一步总结了神经元适应对啮齿动物胡须介导的触觉系统中沿单细胞和群体水平的神经元反应动力学和编码效率的功能影响。基于此处提供的直接和间接证据,我们认为感觉适应为感觉处理中的降噪、显著性处理和异常刺激检测、整合与同时检测之间的转换、带通频率滤波、调整神经元感受野、增强神经编码以及改善适应刺激周围的可辨别性、能量守恒和消除触觉刺激主要特征的编码歧义提供了依赖于上下文的功能机制。