Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
Institute of Behavioural Neuroscience, Department of Experimental Psychology, University College London, London, United Kingdom.
PLoS Comput Biol. 2020 Feb 18;16(2):e1007627. doi: 10.1371/journal.pcbi.1007627. eCollection 2020 Feb.
In primary auditory cortex, slowly repeated acoustic events are represented temporally by the stimulus-locked activity of single neurons. Single-unit studies in awake marmosets (Callithrix jacchus) have shown that a sub-population of these neurons also monotonically increase or decrease their average discharge rate during stimulus presentation for higher repetition rates. Building on a computational single-neuron model that generates stimulus-locked responses with stimulus evoked excitation followed by strong inhibition, we find that stimulus-evoked short-term depression is sufficient to produce synchronized monotonic positive and negative responses to slowly repeated stimuli. By exploring model robustness and comparing it to other models for adaptation to such stimuli, we conclude that short-term depression best explains our observations in single-unit recordings in awake marmosets. Together, our results show how a simple biophysical mechanism in single neurons can generate complementary neural codes for acoustic stimuli.
在初级听觉皮层中，单个神经元的刺激锁定活动以时间方式表示重复缓慢的声刺激。在清醒的卷尾猴（Callithrix jacchus）的单细胞研究中，发现这些神经元中的亚群在更高重复率的刺激呈现期间也会单调地增加或减少其平均放电率。基于一个计算单神经元模型，该模型产生具有刺激引发兴奋随后强烈抑制的刺激锁定反应，我们发现刺激引发的短期抑郁足以产生对缓慢重复刺激的同步单调正响应和负响应。通过探索模型稳健性并将其与其他适应此类刺激的模型进行比较，我们得出结论，短期抑郁最能解释我们在清醒卷尾猴的单细胞记录中的观察结果。总之，我们的结果表明，单个神经元中的简单生物物理机制如何为声刺激产生互补的神经编码。
