Srivastava Kyle H, Holmes Caroline M, Vellema Michiel, Pack Andrea R, Elemans Coen P H, Nemenman Ilya, Sober Samuel J
Biomedical Engineering Doctoral Program, Georgia Institute of Technology and Emory University, Atlanta, GA 30322.
Department of Physics, Emory University, Atlanta, GA 30322.
Proc Natl Acad Sci U S A. 2017 Jan 31;114(5):1171-1176. doi: 10.1073/pnas.1611734114. Epub 2017 Jan 18.
A fundamental problem in neuroscience is understanding how sequences of action potentials ("spikes") encode information about sensory signals and motor outputs. Although traditional theories assume that this information is conveyed by the total number of spikes fired within a specified time interval (spike rate), recent studies have shown that additional information is carried by the millisecond-scale timing patterns of action potentials (spike timing). However, it is unknown whether or how subtle differences in spike timing drive differences in perception or behavior, leaving it unclear whether the information in spike timing actually plays a role in brain function. By examining the activity of individual motor units (the muscle fibers innervated by a single motor neuron) and manipulating patterns of activation of these neurons, we provide both correlative and causal evidence that the nervous system uses millisecond-scale variations in the timing of spikes within multispike patterns to control a vertebrate behavior-namely, respiration in the Bengalese finch, a songbird. These findings suggest that a fundamental assumption of current theories of motor coding requires revision.
神经科学中的一个基本问题是理解动作电位序列（“尖峰信号”）如何编码有关感觉信号和运动输出的信息。尽管传统理论认为此信息由特定时间间隔内发放的尖峰信号总数（发放率）传递，但最近的研究表明，动作电位的毫秒级时间模式（尖峰时间）也携带额外信息。然而，尚不清楚尖峰时间的细微差异是否以及如何驱动感知或行为上的差异，这使得尖峰时间中的信息是否真的在脑功能中起作用尚不清楚。通过检查单个运动单位（由单个运动神经元支配的肌纤维）的活动并操纵这些神经元的激活模式，我们提供了相关和因果证据，证明神经系统利用多峰模式中尖峰时间的毫秒级变化来控制一种脊椎动物行为——即孟加拉雀（一种鸣禽）的呼吸。这些发现表明，当前运动编码理论的一个基本假设需要修正。
