Otolith fibers and terminals in chick vestibular nuclei.
Otolith fibers and terminals in chick vestibular nuclei.
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鸡前庭核中的耳石纤维和末端。
DOI：
10.1002/cne.21273
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Peusner,KennaD
中科院分区：
文献类型：
--
作者：
Popratiloff,Anastas;Peusner,KennaD
通过使用与Alexa Fluor缀合的生物胞素对纤维和终末进行单标记和双标记以及共聚焦成像，研究了4-5日龄幼雏前庭核中重力感觉、耳石传入纤维和终末的分布。前庭核在用MAP 2免疫标记的脑干的一系列五个横切面中表示。囊状纤维在前庭后切核水平后进入延髓，穿过腹侧部，产生升支和降支。小囊状终末在切向核内与少数树突接触。相反，小囊状终末接触前庭腹外侧核、前庭小脑核和前庭降核中的许多树突和少数神经元胞体。椭圆囊纤维走行于中央切向核的腹侧部，然后分叉成升支和降支。在切向核中，椭圆囊纤维形成一些大的轴体末端（勺状末端）和树突上的一些小末端。此外，小椭圆囊终末接触许多树突和少数神经元胞体的腹外侧，前庭小脑，和前庭降核。因此，耳石神经分布的重叠可以忽略不计，尽管每个耳石传入神经与耳道传入神经共享共同的区域，这表明一些二级前庭神经元处理来自耳石和耳道传入神经的会聚输入。结合以前的结果，本研究结果确定了鸡前庭核的离散区域，其中二级前庭神经元可能直接处理会聚耳石和耳道输入。J. Comp.神经元502：19-37，2007.© 2007 Wiley利斯公司
The distribution of gravity‐sensing, otolith afferent fibers and terminals was studied in the vestibular nuclei of 4–5‐day hatchling chicks by using single and double labeling of fibers and terminals with biocytin conjugated to Alexa Fluor and confocal imaging. The vestibular nuclei are represented in a series of five transverse sections of the brainstem immunolabeled with MAP2. Saccular fibers entered the medulla posterior to and at the level of the posterior tangential vestibular nucleus and coursed through ventral parts, producing ascending and descending branches. Small saccular terminals contacted a few dendrites in the tangential nucleus. In contrast, small saccular terminals contacted many dendrites and a few neuron cell bodies in the ventrolateral vestibular nucleus, vestibulocerebellar nucleus, and descending vestibular nuclei. Utricular fibers coursed through ventral parts of the central tangential nucleus before bifurcating into ascending and descending branches. In the tangential nucleus, utricular fibers formed a few large axosomatic terminals (spoon terminals) and a few small terminals on dendrites. In addition, small utricular terminals contacted numerous dendrites and a few neuron cell bodies in the ventrolateral, vestibulocerebellar, and descending vestibular nuclei. Thus, there was negligible overlap in the distribution of the otolith nerves, although each otolith afferent shared common regions with the canal afferents, previously shown, suggesting that some second‐order vestibular neurons process convergent inputs from otolith and canal afferents. Taken together with previous results, the present findings identify discrete regions of the chick vestibular nuclei where second‐order vestibular neurons likely process directly convergent otolith and canal inputs. J. Comp. Neurol. 502:19–37, 2007. © 2007 Wiley‐Liss, Inc.