Functional characterization of spikelet activity in the primary visual cortex.
Functional characterization of spikelet activity in the primary visual cortex.
复制标题
初级视觉皮层小穗活动的功能特征。
DOI：
10.1113/jp270876
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Priebe,NicholasJ
中科院分区：
文献类型：
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作者：
Scholl,Benjamin;Andoni,Sari;Priebe,NicholasJ
猫视皮层活体全细胞膜片钳记录的关键点是神经元的膜电位发生微小的偏转，称为棘波。棘波的统计数据和功能特性表明，这些偏转来自附近的单个细胞。棘波与主神经元有许多共同的感觉选择性，包括定向选择性、感受野位置和眼球偏好。然而，主神经元和小穗通常不共享深度偏好(双眼视差)。小穗活动和膜电位的相互关系揭示了一些主要神经元膜电位的直接影响，表明这些细胞是突触耦合的或接受皮层网络的共同输入。其他小穗-神经元对则显示间接效应，或接受皮层网络的共同输入可能是相关网络事件的结果。摘要新皮质的细胞内记录不仅揭示了神经元的膜电位，还揭示了被称为小穗的微小的单极或双极偏转。小穗被认为来自多种来源，包括活跃的树突机制、缝隙连接和细胞外信号。在这里，我们研究了在活体猫初级视觉皮质神经元中测量到的小穗的功能特征。穗统计数据和我们对小穗活动的功能描述表明，小穗起源于一个单独的、附近的细胞。小穗动力学和超极化电流注入对小穗活动缺乏直接影响表明，它们不是由记录的主神经元的电耦合引起的。小穗表现出与主神经元相匹配的定向调谐偏好和眼球优势。相反，小穗和主神经元的双眼视差偏好并不相关。最后，我们考察了小穗对主神经元膜电位的影响；我们确实观察到了一些记录，其中小穗与主神经元膜电位相关，表明这些神经元是突触耦合的或接受来自皮质网络的共同输入。
Key pointsIn vivowhole‐cell patch‐clamp recordings in cat visual cortex revealed small deflections in the membrane potential of neurons, termed spikelets.Spikelet statistics and functional properties suggest these deflections originate from a single, nearby cell.Spikelets shared a number sensory selectivities with the principal neuron including orientation selectivity, receptive field location and eye preference.Principal neurons and spikelets did not, however, generally share preferences for depth (binocular disparity).Cross‐correlation of spikelet activity and membrane potential revealed direct effects on the membrane potential of some principal neurons, suggesting that these cells were synaptically coupled or received common input from the cortical network.Other spikelet–neuron pairs revealed indirect effects, likely to be the result of correlated network events.AbstractIntracellular recordings in the neocortex reveal not only the membrane potential of neurons, but small unipolar or bipolar deflections that are termed spikelets. Spikelets have been proposed to originate from various sources, including active dendritic mechanisms, gap junctions and extracellular signals. Here we examined the functional characteristics of spikelets measured in neurons from cat primary visual cortexin vivo. Spiking statistics and our functional characterization of spikelet activity indicate that spikelets originate from a separate, nearby cell. Spikelet kinetics and lack of a direct effect on spikelet activity from hyperpolarizing current injection suggest they do not arise from electrical coupling to the principal neuron being recorded. Spikelets exhibited matched orientation tuning preference and ocular dominance to the principal neuron. In contrast, binocular disparity preferences of spikelets and the principal neuron were unrelated. Finally, we examined the impact of spikelets on the principal neuron's membrane potential; we did observe some records for which spikelets were correlated with the membrane potential of the principal neuron, suggesting that these neurons were synaptically coupled or received common input from the cortical network.