Young Brent K, Mindlin Gabriel B, Arneodo Ezequiel, Goller Franz
Department of Biology, University of Utah, Salt Lake City, UT, United States of America.
Physics Department, University of Buenos Aires, Buenos Aires, Argentina.
PeerJ. 2017 Nov 16;5:e4052. doi: 10.7717/peerj.4052. eCollection 2017.
Brain activity during sleep is fairly ubiquitous and the best studied possible function is a role in memory consolidation, including motor memory. One suggested mechanism of how neural activity effects these benefits is through reactivation of neurons in patterns resembling those of the preceding experience. The specific patterns of motor activation replayed during sleep are largely unknown for any system. Brain areas devoted to song production in the songbird brain exhibit spontaneous song-like activity during sleep, but single cell neural recordings did not permit detection of the specific song patterns. We have now discovered that this sleep activation can be detected in the muscles of the vocal organ, thus providing a unique window into song-related brain activity at night. We show that male zebra finches () frequently exhibit spontaneous song-like activity during the night, but that the fictive song patterns are highly variable and uncoordinated compared to the highly stereotyped day-time song production. This substantial variability is not consistent with the idea that night-time activity replays day-time experiences for consolidation. Although the function of this frequent activation is unknown, it may represent a mechanism for exploring motor space or serve to generate internal error signals that help maintain the high stereotypy of day-time song. In any case, the described activity supports the emerging insight that brain activity during sleep may serve a variety of functions.
睡眠期间的大脑活动相当普遍，研究得最为透彻的可能功能是在记忆巩固中发挥作用，包括运动记忆。关于神经活动如何产生这些益处的一种推测机制是，通过以类似于先前经历的模式重新激活神经元。对于任何系统而言，睡眠期间重现的运动激活的具体模式在很大程度上仍是未知的。鸣禽大脑中专门负责歌曲产生的脑区在睡眠期间会表现出类似自发鸣叫的活动，但单细胞神经记录无法检测到具体的歌曲模式。我们现在发现，这种睡眠激活可以在发声器官的肌肉中被检测到，从而为夜间与歌曲相关的大脑活动提供了一个独特的窗口。我们表明，雄性斑胸草雀在夜间经常表现出类似自发鸣叫的活动，但与高度刻板的白天鸣叫产生相比，虚拟鸣叫模式高度可变且不协调。这种显著的变异性与夜间活动为巩固而重现白天经历的观点不一致。尽管这种频繁激活的功能尚不清楚，但它可能代表了一种探索运动空间的机制，或者用于产生内部误差信号，以帮助维持白天鸣叫的高度刻板性。无论如何，所描述的活动支持了一种新出现的观点，即睡眠期间的大脑活动可能具有多种功能。
