Multiple time scales of temporal response in pyramidal and fast spiking cortical neurons
Multiple time scales of temporal response in pyramidal and fast spiking cortical neurons
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DOI：
10.1152/jn.00453.2006
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发表时间：
2006-12-01
影响因子：
2.5
通讯作者：
Fusi, Stefano
中科院分区：
文献类型：
--
作者：
La Camera, Giancarlo;Rauch, Alexander;Fusi, Stefano
在体内，在刺激诱发以及自发活动中发现了在几个时间尺度上相关的神经动力学过程，并且被认为影响感觉刺激的处理方式。尽管其潜在的计算后果，在单个皮层神经元的存在下，多个时间尺度的系统描述是缺乏的。在这项研究中，我们注射快速尖峰和锥体（PYR）神经元在体外与持久的事件的阶梯状和嘈杂的，在体内样电流。几个过程塑造了瞬时尖峰频率的时间过程，这些过程可以减少到少数（1-4）种现象学机制，随着时间的推移降低（适应）或增加（促进）神经元的放电率。不同的适应/易化过程涵盖了广泛的时间尺度，从初始适应（< 10 ms，仅PYR神经元）到快速适应（< 300 ms），早期易化（0.5-1 s，仅PYR）和缓慢（或晚期）适应（秒级）。这些过程的特点是其幅度和时间常数在细胞中的广泛分布，表明多个时间尺度在皮层神经元中起作用，即使在响应静态刺激和存在输入波动的情况下。这些过程可能是级联过程的一部分，负责在几个准备观察到的幂律行为的适应，并可能有深远的计算后果，最近已经描述。
Neural dynamic processes correlated over several time scales are found in vivo, in stimulus-evoked as well as spontaneous activity, and are thought to affect the way sensory stimulation is processed. Despite their potential computational consequences, a systematic description of the presence of multiple time scales in single cortical neurons is lacking. In this study, we injected fast spiking and pyramidal (PYR) neurons in vitro with long-lasting episodes of step-like and noisy, in-vivo-like current. Several processes shaped the time course of the instantaneous spike frequency, which could be reduced to a small number (1-4) of phenomenological mechanisms, either reducing (adapting) or increasing (facilitating) the neuron's firing rate over time. The different adaptation/ facilitation processes cover a wide range of time scales, ranging from initial adaptation (< 10 ms, PYR neurons only), to fast adaptation (< 300 ms), early facilitation (0.5-1 s, PYR only), and slow (or late) adaptation (order of seconds). These processes are characterized by broad distributions of their magnitudes and time constants across cells, showing that multiple time scales are at play in cortical neurons, even in response to stationary stimuli and in the presence of input fluctuations. These processes might be part of a cascade of processes responsible for the power-law behavior of adaptation observed in several preparations, and may have far-reaching computational consequences that have been recently described.