Australian Research Council Centre of Excellence in Vision Science and Save Sight Institute, University of Sydney, Sydney, New South Wales 2001, Australia.
Proc Natl Acad Sci U S A. 2011 Aug 30;108(35):14659-63. doi: 10.1073/pnas.1108004108. Epub 2011 Aug 15.
Slow rhythmic changes in nerve-cell activity are characteristic of unconscious brain states and also may contribute to waking brain function by coordinating activity between cortical and subcortical structures. Here we show that slow rhythms are exhibited by the koniocellular (K) pathway, one of three visual pathways beginning in the eye and projecting through the lateral geniculate visual relay nucleus to the cerebral cortex. We recorded activity in pairs and ensembles of neurons in the lateral geniculate nucleus of anesthetized marmoset monkeys. We found slow rhythms are common in K cells but are rare in parvocellular and magnocellular cell pairs. The time course of slow K rhythms corresponds to subbeta (<10 Hz) EEG frequencies, and high spike rates in K cells are associated with low power in the theta and delta EEG bands. By contrast, spontaneous activity in the parvocellular and magnocellular pathways is neither synchronized nor strongly linked to EEG state. These observations suggest that parallel visual pathways not only carry different kinds of visual signals but also contribute differentially to brain circuits at the first synapse in the thalamus. Differential contribution of sensory streams to rhythmic brain circuits also raises the possibility that sensory stimuli can be tailored to modify brain rhythms.
神经细胞活动的缓慢节律变化是无意识脑状态的特征，也可能通过协调皮质和皮质下结构之间的活动来促进清醒时的大脑功能。在这里，我们表明，在从眼睛开始并通过外侧膝状体视觉中继核投射到大脑皮层的三个视觉通路之一的 koniocellular (K) 通路中表现出缓慢的节律。我们记录了麻醉狨猴外侧膝状体核中神经元对的活动。我们发现，慢速 K 节律在 K 细胞中很常见，但在小细胞和大细胞对中很少见。慢速 K 节律的时程与亚贝塔（<10 Hz）EEG 频率相对应，而 K 细胞中的高尖峰率与 theta 和 delta EEG 带中的低功率相关。相比之下，小细胞和大细胞通路中的自发活动既不同步也与 EEG 状态没有强烈联系。这些观察结果表明，平行的视觉通路不仅携带不同类型的视觉信号，而且在丘脑的第一个突触对大脑回路的贡献也不同。感觉流对节律性大脑回路的不同贡献也提出了这样一种可能性，即感觉刺激可以被定制以改变大脑节律。
