NMDAR-dependent control of call duration in Xenopus laevis.
NMDAR-dependent control of call duration in Xenopus laevis.
复制标题
非洲爪蟾呼叫持续时间的 NMDAR 依赖性控制。
DOI：
10.1152/jn.00155.2010
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发表时间：
2010
影响因子：
2.5
通讯作者：
Yamaguchi,Ayako
中科院分区：
文献类型：
--
作者：
Zornik,Erik;Katzen,AbrahamW;Rhodes,HeatherJ;Yamaguchi,Ayako
许多有节奏的行为，如运动和发声，都涉及到时间动态模式。大脑是如何产生时间复杂性的？在这里，我们使用非洲爪蟾的声音中枢模式发生器（CPG）来解决这个问题。孤立的大脑可以引发有效的发声，使我们能够在体外研究CPG。X. laevis广告调用是暂时调制的；呼叫由有节奏的滴答颤音组成，在快速（~ 60赫兹）和缓慢（~ 30赫兹）之间交替。我们研究了两个CPG核-喉运动核（n.IX-X）和延髓背被盖区(DTAM) -在设定节律频率和呼叫持续时间中的作用。我们发现DTAM的局部场电位波与有效的快速颤音相一致，与有效的咔哒声相一致。在中断n.IX-X连接后，波仍然存在，而相活动消失。波的持续时间与温度有关，并与有效的快颤音相关。当波的持续时间被温度操纵改变时，这种相关性仍然存在。选择性地冷却DTAM，而不是n.IX-X，延长了有效的呼叫和快速颤音持续时间，而冷却任何一个核都减慢了有效的点击率。然后，甲基d-天冬氨酸受体（NMDAR）拮抗剂dapv阻断了波和有效的快颤音，表明波控制了快颤音的激活，从而控制了通话持续时间。我们得出结论，存在两个功能不同的CPG电路：1)DTAM中的模式生成器决定呼叫持续时间，2)节奏生成器（跨越DTAM和n.IX-X）决定点击率。新发现的DTAM模式发生器为理解ndmar依赖的节律电路提供了一个很好的模型。
Many rhythmic behaviors, such as locomotion and vocalization, involve temporally dynamic patterns. How does the brain generate temporal complexity? Here, we use the vocal central pattern generator (CPG) of Xenopus laevis to address this question. Isolated brains can elicit fictive vocalizations, allowing us to study the CPG in vitro. The X. laevis advertisement call is temporally modulated; calls consist of rhythmic click trills that alternate between fast (∼60 Hz) and slow (∼30 Hz) rates. We investigated the role of two CPG nuclei—the laryngeal motor nucleus (n.IX–X) and the dorsal tegmental area of the medulla (DTAM)—in setting rhythm frequency and call durations. We discovered a local field potential wave in DTAM that coincides with fictive fast trills and phasic activity that coincides with fictive clicks. After disrupting n.IX–X connections, the wave persists, whereas phasic activity disappears. Wave duration was temperature dependent and correlated with fictive fast trills. This correlation persisted when wave duration was modified by temperature manipulations. Selectively cooling DTAM, but not n.IX–X, lengthened fictive call and fast trill durations, whereas cooling either nucleus decelerated the fictive click rate. TheN-methyl-d-aspartate receptor (NMDAR) antagonistdAPV blocked waves and fictive fast trills, suggesting that the wave controls fast trill activation and, consequently, call duration. We conclude that two functionally distinct CPG circuits exist:1) a pattern generator in DTAM that determines call duration and2) a rhythm generator (spanning DTAM and n.IX–X) that determines click rates. The newly identified DTAM pattern generator provides an excellent model for understanding NDMAR-dependent rhythmic circuits.