Development of Twitching in Sleeping Infant Mice Depends on Sensory Experience
Development of Twitching in Sleeping Infant Mice Depends on Sensory Experience
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DOI：
10.1016/j.cub.2015.01.022
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发表时间：
2015-03-02
期刊：
影响因子：
9.2
通讯作者：
McMurray, Bob
中科院分区：
文献类型：
--
作者：
Blumberg, Mark S.;Coleman, Cassandra M.;McMurray, Bob
肌阵挛性抽搐是在哺乳动物的主动（或REM）睡眠期间，特别是在早期发育中专门和大量发生的急动运动[1-4]。在大鼠幼崽中，肢体抽搐表现出复杂的时空结构，在早期发育中发生变化[5]。然而，目前尚不清楚这种发育变化是否受到感觉经验的影响，这是抽搐的感觉反馈不仅激活感觉运动回路，而且修改它们的前提条件[4]。在这里，我们研究了本体感觉对新生ErbB 2条件性敲除小鼠抽搐的贡献，这些小鼠缺乏肌梭，长大后表现出功能障碍的本体感觉[6-8]。前肢抽搐的高速摄像意外地揭示了一类反射样抽搐，包括激动剂抽搐，随后立即由拮抗剂抽搐，其在出生后在野生型/杂合子中发展，但在敲除中没有。与成人的证据相反，脊髓反射在抽搐期间受到抑制[9-11]，这一发现表明抽搐触发单突触牵张反射，并通过这样做促进其活动依赖性发育[12-14]。接下来，我们评估了频率和组织的发展变化（即，熵）的更复杂的，多关节的抽搐模式;再次，野生型/杂合子表现出抽搐模式的发育变化，这在敲除中没有看到。因此，有针对性地删除一个外围传感器改变了正常的发展，当地和全球的功能抽搐，表明抽搐是由感官经验。这些结果也突出了抽搐作为一种独特的信息诊断工具，用于评估脊髓和脊髓上回路的功能状态的潜在用途。
Myoclonic twitches are jerky movements that occur exclusively and abundantly during active (or REM) sleep in mammals, especially in early development [1-4]. In rat pups, limb twitches exhibit a complex spatiotemporal structure that changes across early development [5]. However, it is not known whether this developmental change is influenced by sensory experience, which is a prerequisite to the notion that sensory feedback from twitches not only activates sensorimotor circuits but modifies them [4]. Here, we investigated the contributions of proprioception to twitching in newborn ErbB2 conditional knockout mice that lack muscle spindles and grow up to exhibit dysfunctional proprioception [6-8]. High-speed videography of forelimb twitches unexpectedly revealed a category of reflex-like twitching comprising an agonist twitch followed immediately by an antagonist twitch that developed postnatally in wild-types/heterozygotes, but not in knockouts. Contrary to evidence from adults that spinal reflexes are inhibited during twitching [9-11], this finding suggests that twitches trigger the monosynaptic stretch reflex and, by doing so, contribute to its activity-dependent development [12-14]. Next, we assessed developmental changes in the frequency and organization (i.e., entropy) of more-complex, multi-joint patterns of twitching; again, wild-types/heterozygotes exhibited developmental changes in twitch patterning that were not seen in knockouts. Thus, targeted deletion of a peripheral sensor alters the normal development of local and global features of twitching, demonstrating that twitching is shaped by sensory experience. These results also highlight the potential use of twitching as a uniquely informative diagnostic tool for assessing the functional status of spinal and supraspinal circuits.