非快速眼动睡眠的睡眠纺锤是短暂的,10-16Hz脑电图振荡,其皮质同步取决于丘脑-皮质环的参与。然而,先前在因发育不全或全call切开术而缺乏call体的动物模型以及患有call体发育不全的人类中进行的研究表明,皮质-皮质连接在皮质(半球间)纺锤体同步中也可能具有相关作用。然而,这些作品中的大多数没有提供直接的定量分析来支持他们的观察。通过研究一个罕见的callosotomized样本,裂脑患者,我们最近证明,call体的完全切除与非REM慢波的半球间传播显着减少有关。有趣的是,睡眠纺锤波通常在时间和空间上围绕慢波(0.5-4Hz)分组,这种协调被认为在睡眠依赖性学习和记忆巩固中具有重要作用。鉴于这些前提,在这里,我们着手调查全call切开术是否会影响睡眠纺锤波的产生和传播,以及它们与睡眠慢波的耦合。为了这个目标,我们分析了5例因耐药性癫痫(年龄40-53岁,两名女性)而接受全call切开术的患者的夜间高密度脑电图记录(256个电极),3名非颅骨切开术神经科患者(年龄44-66岁,2名女性),以及24名健康成人对照受试者(年龄20-47岁,13名女性)的样本。使用经过验证的算法自动检测各个睡眠纺锤,并计算其属性和地形分布。所有分析都是在有和没有基于回归的调整的情况下进行的,这些调整考虑了受试者之间的年龄差异。骨化术患者和健康受试者之间的比较没有发现纺锤体密度的系统变化,振幅或频率。然而,骨切开术患者的特点是纺锤体持续时间减少,这可能代表了两个半球皮层区域的纺锤体活动更快的去同步的结果。与我们之前关于睡眠慢波的发现相反,我们没能检测到任何清晰的,睡眠纺锤的半球间同步的系统变化。与此相符,callosotomized患者的特征是时间耦合纺锤体和慢波之间的空间关联的扩展减少。我们的发现与纺锤体对人类丘脑-皮质而不是皮质-皮质连接的依赖性一致,但也透露,尽管他们的时间关联,慢波和纺锤在地形表达方面是独立调节的。
Sleep spindles of non-REM sleep are transient, waxing-and-waning 10-16 Hz EEG oscillations, whose cortical synchronization depends on the engagement of thalamo-cortical loops. However, previous studies in animal models lacking the corpus callosum due to agenesis or total callosotomy and in humans with agenesis of the corpus callosum suggested that cortico-cortical connections may also have a relevant role in cortical (inter-hemispheric) spindle synchronization. Yet, most of these works did not provide direct quantitative analyses to support their observations. By studying a rare sample of callosotomized, split-brain patients, we recently demonstrated that the total resection of the corpus callosum is associated with a significant reduction in the inter-hemispheric propagation of non-REM slow waves. Interestingly, sleep spindles are often temporally and spatially grouped around slow waves (0.5-4 Hz), and this coordination is thought to have an important role in sleep-dependent learning and memory consolidation. Given these premises, here we set out to investigate whether total callosotomy may affect the generation and spreading of sleep spindles, as well as their coupling with sleep slow waves. To this aim, we analysed overnight high-density EEG recordings (256 electrodes) collected in five patients who underwent total callosotomy due to drug-resistant epilepsy (age 40-53, two females), three non-callosotomized neurological patients (age 44-66, two females), and in a sample of 24 healthy adult control subjects (age 20-47, 13 females). Individual sleep spindles were automatically detected using a validated algorithm and their properties and topographic distributions were computed. All analyses were performed with and without a regression-based adjustment accounting for inter-subject age differences. The comparison between callosotomized patients and healthy subjects did not reveal systematic variations in spindle density, amplitude or frequency. However, callosotomized patients were characterized by a reduced spindle duration, which could represent the result of a faster desynchronization of spindle activity across cortical areas of the two hemispheres. In contrast with our previous findings regarding sleep slow waves, we failed to detect in callosotomized patients any clear, systematic change in the inter-hemispheric synchronization of sleep spindles. In line with this, callosotomized patients were characterized by a reduced extension of the spatial association between temporally coupled spindles and slow waves. Our findings are consistent with a dependence of spindles on thalamo-cortical rather than cortico-cortical connections in humans, but also revealed that, despite their temporal association, slow waves and spindles are independently regulated in terms of topographic expression.