Department of Animal and Human Physiology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
Department of Animal and Human Physiology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
Behav Brain Res. 2014 May 15;265:84-92. doi: 10.1016/j.bbr.2014.02.023. Epub 2014 Feb 22.
Hippocampal theta rhythm appears in two vigilance states: active waking and paradoxical sleep. The ventral tegmental area (VTA) is active in sleep and waking and is connected to the hippocampus. We assessed the relationship between local field potential (LFP) of the VTA and sleep-waking stages in freely moving rats. Electrical activity of the VTA was divided into: quiet waking (W), waking with theta (WT), slow wave sleep (SWS) and paradoxical sleep (PS), depending on the hippocampal signal and the animal's behavior. We analyzed total power in the VTA signal and we also extracted peak power (Pmax) and corresponding frequency (Fmax) in theta and delta bands from both the VTA and hippocampal recording. In the VTA the 6-9 Hz band had the highest power during PS, and the ratio of the 6-9 to 3-6 Hz power was highest during both PS and WT, which accentuated Pmax of this particular theta sub-band. During W, a very slight increase (or plateau) in signal power was seen in theta range. Pmax and Fmax of theta were higher in PS than in both WT and W, and these parameters did not differ between W and WT. During WT and PS, Fmax in the 6-9 Hz band was greatly correlated between the VTA and hippocampus signal. We also detected high cross-correlation in power spectra between the hippocampus and the VTA (for delta and theta, during WT and PS). The results suggest that the VTA may belong to the broad network involved in theta rhythm induction.
海马体θ节律出现在两种警觉状态：主动觉醒和矛盾睡眠。腹侧被盖区（VTA）在睡眠和觉醒时活跃，并与海马体相连。我们评估了自由活动大鼠海马体信号和动物行为的 VTA 局部场电位（LFP）与睡眠-觉醒阶段之间的关系。VTA 的电活动分为：安静觉醒（W）、伴有θ波的觉醒（WT）、慢波睡眠（SWS）和矛盾睡眠（PS）。我们分析了 VTA 信号的总功率，还从 VTA 和海马体记录中提取了θ和δ波段的峰值功率（Pmax）和相应频率（Fmax）。在 VTA 中，6-9 Hz 频段在 PS 期间具有最高的功率，而在 PS 和 WT 期间，6-9 至 3-6 Hz 的功率比最高，这突出了该特定θ亚带的 Pmax。在 W 期间，在θ范围内观察到信号功率的轻微增加（或平台）。PS 期间的 Pmax 和 Fmax 均高于 WT 和 W，WT 和 W 之间这些参数没有差异。在 WT 和 PS 期间，VTA 和海马体信号之间 6-9 Hz 频段的 Fmax 相关性很强。我们还在 WT 和 PS 期间检测到了海马体和 VTA 之间功率谱的高互相关（对于δ和θ）。结果表明，VTA 可能属于参与θ节律诱导的广泛网络。
