Efficient population coding of naturalistic whisker motion in the ventro-posterior medial thalamus based on precise spike timing.
Efficient population coding of naturalistic whisker motion in the ventro-posterior medial thalamus based on precise spike timing.
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DOI：
10.3389/fncir.2015.00050
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发表时间：
2015
影响因子：
3.5
通讯作者：
Petersen RS
中科院分区：
文献类型：
--
作者：
Bale MR;Ince RA;Santagata G;Petersen RS
啮齿类动物的胡须相关核(VPM)包含一个体视图，其中胡须的代表被分为不同的神经元亚群，称为“Barreloid”。每个杆状突起投射到其相关的皮质桶柱上，从而形成进入桶皮质的感觉刺激的通道。我们的目标是确定一个棒状体内的神经元群体如何编码自然主义的胡须运动。在大鼠中，我们通过植入平行于Barreloid纵轴的硅探针，记录了单个Barreloid内多达9个单个神经元的细胞外活动。我们发现，纹理诱导的胡须运动的回放引起了稀疏的反应，时间精确到毫秒。在种群水平上，存在同步活动：然而，不同的神经元亚群在不同的时间同步活动。种群反应和胡须运动之间的互信息随着种群大小而近乎线性地增加。当归一化以排除激发频率差异时，我们发现纹理编码具有比白噪声更高的信息效率。这些结果表明，在每个VPM条形体内，有一个丰富而有效的种群代码，用于基于精确计时的种群尖峰模式的自然主义胡须运动。
The rodent whisker-associated thalamic nucleus (VPM) contains a somatotopic map where whisker representation is divided into distinct neuronal sub-populations, called “barreloids”. Each barreloid projects to its associated cortical barrel column and so forms a gateway for incoming sensory stimuli to the barrel cortex. We aimed to determine how the population of neurons within one barreloid encodes naturalistic whisker motion. In rats, we recorded the extracellular activity of up to nine single neurons within a single barreloid, by implanting silicon probes parallel to the longitudinal axis of the barreloids. We found that play-back of texture-induced whisker motion evoked sparse responses, timed with millisecond precision. At the population level, there was synchronous activity: however, different subsets of neurons were synchronously active at different times. Mutual information between population responses and whisker motion increased near linearly with population size. When normalized to factor out firing rate differences, we found that texture was encoded with greater informational-efficiency than white noise. These results indicate that, within each VPM barreloid, there is a rich and efficient population code for naturalistic whisker motion based on precisely timed, population spike patterns.