Department of Life Sciences, Institute for Multidisciplinary Research, 11000 Belgrade, Serbia.
J Physiol Pharmacol. 2009 Dec;60(4):79-84.
The experiments were performed in 14 adult, male Sprague Dawley rats chronically instrumented for sleep recording and recorded during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. In our former study we demonstrated that the systemically induced lesion of the noradrenergic or serotonergic axon terminals did not affect the sleep-wake distribution from control condition. In this study, by using spectral analysis and phase shift spectra of the cortical and pontine EEG we analyzed cortico-pontine theta oscillation synchronization phase shift on 6-hour recordings in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Our results demonstrated for the first time that chronically decreased brain monoamines in freely moving rats changed cortico-pontine theta synchronization phase shift. Pons became a leading theta oscillator. We assume that deficit of monoamines induced predominance of the NREM/REM transitions, characterized with phasic theta oscillations (the increased density of clustered P waves which intrinsic frequency corresponds to theta frequency oscillations), and may produced preceding phasic theta versus tonic theta oscillation drive.
实验在 14 只成年雄性 Sprague Dawley 大鼠中进行，这些大鼠被长期用于睡眠记录，并在基础状态下、假注射（腹腔注射 1ml/kg 生理盐水）后以及注射全身神经毒素（DSP-4 或 PCA；1ml/kg，腹腔注射）后每周进行 5 周，以化学切断蓝斑（LC）和中缝背核（DR）轴突末梢。在我们之前的研究中，我们证明了系统诱导的去甲肾上腺素能或 5-羟色胺能轴突末梢损伤不会影响从对照条件下的睡眠-觉醒分布。在这项研究中，我们通过使用皮质和脑桥 EEG 的频谱分析和相移谱，分析了在对照条件下和单胺能损伤后 28 天的 6 小时记录中皮质-脑桥θ振荡同步相移，作为 DR 或 LC 化学轴突切断永久建立的时间。我们的研究结果首次表明，在自由活动的大鼠中，慢性降低的脑单胺类物质改变了皮质-脑桥θ同步相移。脑桥成为主要的θ振荡器。我们假设单胺类物质的缺乏诱导了 NREM/REM 转换的优势，其特征是相位θ振荡（簇状 P 波的密度增加，其固有频率对应于θ频率振荡），并且可能产生了先前的相位θ相对于紧张性θ振荡驱动。
