Chorda tympani nerve terminal field maturation and maintenance is severely altered following changes to gustatory nerve input to the nucleus of the solitary tract.
Chorda tympani nerve terminal field maturation and maintenance is severely altered following changes to gustatory nerve input to the nucleus of the solitary tract.
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DOI：
10.1523/jneurosci.0151-11.2011
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发表时间：
2011-05-25
期刊：
影响因子：
--
通讯作者：
Hill DL
中科院分区：
文献类型：
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作者：
Corson SL;Hill DL
多个输入之间的神经竞争可以影响感觉系统终末场的细化和维持。在大鼠味觉系统中，鼓索、岩浅大神经和舌咽神经在第一中枢中继-孤束核（NTS）中具有不同但重叠的终末野。这种重叠是最大的，在出生后早期的年龄，随后显着的细化和修剪的领域超过三个星期的时间，这表明竞争机制的基础修剪。在这里，我们操纵了假定的竞争性相互作用的三个神经切片的大岩浅神经和舌咽神经在出生后第15天（P15），P25，或在成年，而保持完整的鼓索神经。神经切片后35天（切片神经功能再生之前的一段时间）评估了鼓索神经的终末区域。无论年龄时，神经被切断，鼓索神经终末领域扩大到一个体积比假对照组的四倍。终末场密度测量显示，扩大的终末场与P15对照大鼠相似。因此，它似乎鼓索神经终末字段默认其出生后早期字段的大小和形状时，重叠领域的神经被切断，这种解剖可塑性保留到成年。这些发现不仅证明了中枢味觉系统的戏剧性和终身可塑性，而且还表明，功能和味觉相关行为的相应变化将伴随脑干回路损伤引起的变化。
Neural competition among multiple inputs can affect the refinement and maintenance of terminal fields in sensory systems. In the rat gustatory system, the chorda tympani, greater superficial petrosal, and glossopharyngeal nerves have distinct but overlapping terminal fields in the first central relay, the nucleus of the solitary tract (NTS). This overlap is largest at early postnatal ages followed by a significant refinement and pruning of the fields over a three-week period, suggesting that competitive mechanisms underlie the pruning. Here, we manipulated the putative competitive interactions among the three nerves by sectioning the greater superficial petrosal and glossopharyngeal nerves at postnatal day 15 (P15), P25, or at adulthood, while leaving the chorda tympani nerve intact. The terminal field of the chorda tympani nerve was assessed 35 days following nerve sections, a period before the sectioned nerves functionally regenerated. Regardless of the age when the nerves were cut, the chorda tympani nerve terminal field expanded to a volume four times larger than sham controls. Terminal field density measurements revealed that the expanded terminal field was similar to P15 control rats. Thus, it appears that the chorda tympani nerve terminal field defaults to its early postnatal field size and shape when the nerves with overlapping fields are cut, and this anatomical plasticity is retained into adulthood. These findings not only demonstrate the dramatic and lifelong plasticity in the central gustatory system, but also suggest that corresponding changes in functional and taste-related behaviors will accompany injury-induced changes in brainstem circuits.