Valjakka A, Vartiainen J, Tuomisto L, Tuomisto J T, Olkkonen H, Airaksinen M M
Department of Pharmacology, University of Kuopio, Finland.
Brain Res Bull. 1998 Sep 15;47(2):171-84. doi: 10.1016/s0361-9230(98)00006-9.
The fasciculus retroflexus (FR) fiber bundle comprises the intense cholinergic projection from the medial division of the habenula nucleus (Hbn) of the epithalamus to the interpeduncular nucleus (IPN) of the limbic midbrain. Due to the widespread connections of the Hbn and IPN, it could be surmised that the FR is integrated in the processings of various subsystems that are known to be involved in the sleep-wake mechanisms; relevant sites include the limbic forebrain and midbrain areas and more caudal pontine structures. Consequently, the present study addressed the significance of the FR in the spontaneous sleep-wake stage-associated variations of the different activity patterns of frontal cortex and hippocampal electroencephalograms (EEGs), the electrooculogram, and body movements, in freely behaving rats that had been subjected to either bilateral electrolytic lesioning of the FR or control operations. The evolution of different state combinations was assessed by the combinatory analysis of different activity stages appearing on the 6-h records. As compared to the control-operated group, the FR lesioning substantially reduced the time spent in rapid eye movement (REM) sleep by 79%, moderately decreased the duration of the intermediate state of sleep by 29%, and quiet waking state by 44%, but had virtually no effects on the durations of different types of non-REM sleep (i.e., drowsiness that which involved quiet sleep or slow-wave sleep containing delta and spindle state components) or on the times of active waking behavior that corresponded to the body movements. Quantitative decomposition analyses revealed marked variations in the frontal cortex and hippocampal activity as well as REM during the course of the extracted sleep-wake stages described and there were also some group differences. Of those individual features that were used to determine different sleep-wake stages, the overall hippocampal theta time (41% decrease) and single REM frequency (71% reduction during the REM sleep) were most affected. In contrast, the various properties of desynchronization/synchronization patterns of frontal cortex EEGs were consistently hardly influenced by the FR lesioning. Therefore, the present data suggest the involvement of the FR in the REM sleep processes by establishing prominent associations with the limbic and REM control mechanisms that involve the hippocampus and plausibly pontine ocular activity networks.
后屈束（FR）纤维束包含从丘脑上核缰核（Hbn）内侧部分到边缘中脑脚间核（IPN）的强烈胆碱能投射。由于Hbn和IPN广泛的连接，可以推测FR整合于已知参与睡眠 - 觉醒机制的各种子系统的处理过程中；相关部位包括边缘前脑和中脑区域以及更靠尾侧的脑桥结构。因此，本研究探讨了在自由活动的大鼠中，FR对额叶皮质和海马脑电图（EEG）、眼电图以及身体运动的不同活动模式与自发睡眠 - 觉醒阶段相关变化的意义，这些大鼠接受了FR的双侧电解损伤或对照手术。通过对6小时记录中出现的不同活动阶段进行组合分析来评估不同状态组合的演变。与对照手术组相比，FR损伤使快速眼动（REM）睡眠所花费的时间大幅减少了79%，适度减少了睡眠中间状态的持续时间29%，安静觉醒状态减少了44%，但对不同类型的非REM睡眠（即涉及安静睡眠或包含δ和纺锤波状态成分的慢波睡眠的嗜睡）的持续时间或与身体运动相对应的主动觉醒行为时间几乎没有影响。定量分解分析显示，在所描述的提取的睡眠 - 觉醒阶段过程中，额叶皮质和海马活动以及REM存在明显变化，并且也存在一些组间差异。在用于确定不同睡眠 - 觉醒阶段的那些个体特征中，总体海马θ波时间（减少41%）和单个REM频率（REM睡眠期间减少71%）受影响最大。相比之下，额叶皮质EEG的去同步化/同步化模式的各种特性一直几乎不受FR损伤的影响。因此，目前的数据表明FR通过与涉及海马和可能的脑桥眼动活动网络的边缘和REM控制机制建立显著关联而参与REM睡眠过程。
