Health and Medical Services Center, Shiga University, Shiga, Japan.
Brain Res. 2011 May 10;1389:83-92. doi: 10.1016/j.brainres.2011.02.061. Epub 2011 Mar 5.
Previous neuroimaging studies that examined cerebral blood flow during rapid eye movement (REM) sleep have reported inconsistent findings regarding the activity of the dorsolateral prefrontal cortex (DLPFC). Although most previous positron emission tomography (PET) studies failed to detect DLPFC activation during REM sleep, several studies have observed DLPFC activation, possibly reflecting transient prefrontal activities related to REM. More recently, an event-related functional magnetic resonance imaging (fMRI) study observed REM-locked activation of the DLPFC during REM sleep. The present study investigated hemodynamic changes of the DLPFC throughout the REM sleep period in 25 subjects using near-infrared spectroscopy. Continuous monitoring of changes in the hemoglobin (Hb) concentration and tissue oxygenation index (TOI, proportion of oxygenated-Hb to total-Hb) in the bilateral DLPFC was conducted every 0.5s, simultaneously with polysomnographic recordings. Eight of the 25 subjects showed REM sleep, and all indicated a clear increase in both the oxygenated-Hb concentration and TOI from baseline at the occurrence of first REM, relative to prior stage 2 sleep. The results indicate that the appearance of the first REM that occurred just after onset of the REM sleep closely coincides with the activation of the DLPFC, which could play a role in cognitive activities during REM sleep in humans.
先前研究快速眼动（REM）睡眠期间大脑血流的神经影像学研究报告了背外侧前额叶皮质（DLPFC）活动的不一致发现。尽管大多数先前的正电子发射断层扫描（PET）研究未能在 REM 睡眠期间检测到 DLPFC 激活，但一些研究观察到了 DLPFC 激活，这可能反映了与 REM 相关的短暂前额叶活动。最近，一项事件相关功能磁共振成像（fMRI）研究观察到在 REM 睡眠期间 DLPFC 的 REM 锁定激活。本研究使用近红外光谱在 25 名受试者中研究了整个 REM 睡眠期间 DLPFC 的血液动力学变化。在每 0.5 秒连续监测双侧 DLPFC 中的血红蛋白（Hb）浓度和组织氧合指数（TOI，含氧 Hb 与总 Hb 的比例）的变化，同时进行多导睡眠图记录。25 名受试者中有 8 名出现了 REM 睡眠，并且所有受试者在首次 REM 出现时，与之前的 2 期睡眠相比，含氧 Hb 浓度和 TOI 均明显增加。结果表明，刚刚发生 REM 睡眠时出现的首次 REM 与 DLPFC 的激活密切相关，这可能在 REM 睡眠期间的认知活动中发挥作用。
