Laboratory of Biomodeling, Graduate School of Information Sciences, Tohoku University, Sendai, Japan.
J Neurophysiol. 2010 May;103(5):2318-25. doi: 10.1152/jn.00551.2009. Epub 2010 Feb 17.
Theta waves in the amygdala are known to be synchronized with theta waves in the hippocampus. Synchronization between amygdala and hippocampal theta waves is considered important for neuronal communication between these regions during the memory-retrieval process. These theta waves are also observed during rapid eye movement (REM) sleep. However, few studies have examined the mechanisms and functions of theta waves during REM sleep. This study examined correlations between the dynamics of hippocampal and amygdala theta waves and pontine (P) waves in the subcoeruleus region, which activates many brain areas including the hippocampus and amygdala, during REM sleep in rats. We confirmed that the frequency of hippocampal theta waves increased in association with P wave density, as shown in our previous study. The frequency of amygdala theta waves also increased with in associated with P wave density. In addition, we confirmed synchronization between hippocampal and amygdala theta waves during REM sleep in terms of the cross-correlation function and found that this synchronization was enhanced in association with increased P wave density. We further studied theta wave synchronization associated with P wave density by lesioning the pontine subcoeruleus region. This lesion not only decreased hippocampal and amygdala theta frequency, but also degraded theta wave synchronization. These results indicate that P waves enhance synchronization between regional theta waves. Because hippocampal and amygdala theta waves and P waves are known to be involved in learning and memory processes, these results may help clarify these functions during REM sleep.
杏仁核中的θ波已知与海马体中的θ波同步。在记忆检索过程中，这些区域之间的神经元通信被认为与杏仁核和海马体θ波的同步很重要。这些θ波也在快速眼动 (REM) 睡眠期间观察到。然而，很少有研究检查 REM 睡眠期间θ波的机制和功能。本研究检查了在大鼠 REM 睡眠期间，海马体和杏仁核θ波与桥脑被盖下区（P）波之间的动力学之间的相关性，该区域激活了包括海马体和杏仁核在内的许多大脑区域。我们证实，如我们之前的研究所示，海马体θ波的频率与 P 波密度增加相关。杏仁核θ波的频率也随着 P 波密度的增加而增加。此外，我们通过损伤桥脑被盖下区来确认 REM 睡眠中海马体和杏仁核θ波之间的同步性，通过互相关函数来发现这种同步性随着 P 波密度的增加而增强。我们通过损伤桥脑被盖下区进一步研究了与 P 波密度相关的θ波同步性。该损伤不仅降低了海马体和杏仁核θ波的频率，而且还降低了θ波同步性。这些结果表明 P 波增强了区域θ波之间的同步性。因为已知海马体和杏仁核θ波与 P 波参与学习和记忆过程，所以这些结果可能有助于阐明 REM 睡眠期间的这些功能。
