Baranauskas Gytis, Svirskis Gytis, Tkatch Tatiana
Neurophysiology Laboratory, Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Neuroreport. 2016 Feb 10;27(3):203-8. doi: 10.1097/WNR.0000000000000525.
In the superior colliculus, visual stimuli can induce gamma frequency oscillations of neuronal activity. It has been shown that in cats, these oscillations are synchronized over distances of greater than 300 μm that may contribute toward visual information processing. We investigated the spatial properties of such oscillations in a rodent because the availability of molecular tools could enable future studies on the role of these oscillations in visual information processing. Using extracellular electrode array recordings in anesthetized rats, we found that visual stimuli-induced gamma and eta frequency (30-115 Hz) oscillations of the local field potential that were synchronized over distances of ∼ 600 μm. Multiple-unit events were phase locked to the local field potential signal and showed prominent oscillations during OFF responses. The rate of lower than 5 ms cross-electrode coincidences was in line with the response-corrected predictions for each electrode. These data suggest that the synchronized superior colliculus neuronal activity is largely network driven, whereas common synaptic inputs play a minor role.
在中脑上丘，视觉刺激可诱发神经元活动的伽马频率振荡。研究表明，在猫中，这些振荡在大于300μm的距离上是同步的，这可能有助于视觉信息处理。我们在啮齿动物中研究了此类振荡的空间特性，因为分子工具的可用性能够使未来对这些振荡在视觉信息处理中的作用进行研究。通过在麻醉大鼠中使用细胞外电极阵列记录，我们发现视觉刺激诱发的局部场电位的伽马和埃塔频率（30 - 115Hz）振荡在约600μm的距离上是同步的。多单元事件与局部场电位信号锁相，并在关闭反应期间显示出明显的振荡。低于5ms的跨电极重合率与每个电极的反应校正预测一致。这些数据表明，中脑上丘神经元活动的同步主要由网络驱动，而共同的突触输入起次要作用。
