Relationships between neuronal birthdates and tonotopic positions in the mouse cochlear nucleus.
Relationships between neuronal birthdates and tonotopic positions in the mouse cochlear nucleus.
复制标题
DOI：
10.1002/cne.24575
复制
发表时间：
2019-04-01
期刊：
影响因子：
--
通讯作者：
Yu WM
中科院分区：
文献类型：
--
作者：
Shepard AR;Scheffel JL;Yu WM
音调是脊椎动物听觉系统的一个重要解剖学特征，但对其发育机制知之甚少。由于神经元的出生日期与耳蜗中的音调位置相关，我们研究了它是否也与耳蜗核中的音调位置相关。在耳蜗中，螺旋神经节神经元根据出生日期沿着耳蜗的长度以基底到顶端的进程组织，基底中的神经元（对高频声音有反应）在小鼠胚胎日（E）9.5-10.5左右早期出生，而顶端中的神经元（对低频声音有反应）在E12.5 - 13.5左右晚期出生。使用低剂量的胸苷类似物掺入试验，我们检查是否耳蜗核神经元的空间梯度排列，根据他们的出生日期。大多数耳蜗核神经元出生于E10.5至E13.5之间，峰值在E12.5。在耳蜗背核中观察到神经元出生的第二波，开始于E14.5，持续到E18.5。大的兴奋性神经元在第一波中产生，小的局部回路神经元在第二波中产生。耳蜗背核细胞的出生没有空间梯度。相反，在前腹侧耳蜗核（AVCN）的神经元被发现安排在背腹侧的进展，根据他们的出生日期，这是一致的tonotopic轴。这些AVCN神经元大多数是由endbulb支配的丛状细胞。出生日期和tonotopic位置之间的相关性表明tonotopic位置的规格可测试的机制。我们研究了耳蜗核神经元的出生日期是否决定了它们的音调位置。我们发现，背腹侧耳蜗核，这是在与tonotopic轴一致的神经梯度。相反，在耳蜗背核中没有观察到神经源性梯度。
Tonotopy is a key anatomical feature of the vertebrate auditory system, but little is known about the mechanisms underlying its development. Since date of birth of a neuron correlates with tonotopic position in the cochlea, we investigated if it also correlates with tonotopic position in the cochlear nucleus. In the cochlea, spiral ganglion neurons are organized in a basal to apical progression along the length of the cochlea based on birthdates, with neurons in the base (responding to high-frequency sounds) born early around mouse embryonic day (E) 9.5-10.5, and those in the apex (responding to low-frequency sounds) born late around E12.5 to 13.5. Using a low-dose thymidine analog incorporation assay, we examine whether cochlear nucleus neurons are arranged in a spatial gradient according to their birthdates. Most cochlear nucleus neurons are born between E10.5 to E13.5, with a peak at E12.5. A second wave of neuron birth was observed in the dorsal cochlear nucleus beginning on E14.5 and lasts until E18.5. Large excitatory neurons were born in the first wave and small local circuit neurons were born in the second. No spatial gradient of cell birth was observed in the dorsal cochlear nucleus. In contrast, neurons in the anteroventral cochlear nucleus (AVCN) were found to be arranged in a dorsal to ventral progression according to their birthdates, which is aligned with the tonotopic axis. Most of these AVCN neurons are endbulb-innervated bushy cells. The correlation between birthdate and tonotopic position suggests testable mechanisms for specification of tonotopic position. We investigated whether the birthdate of neurons in the cochlear nucleus defines their tonotopic positions. We found a dorsal to ventral neurogenic gradient in the anteroventral cochlear nucleus, which is in alignment with the tonotopic axis. In contrast, no neurogenic gradient can be observed in the dorsal cochlear nucleus.
登录
查看更多内容
影响因子：
16.2
作者：
He S;Li Z;Ge S;Yu YC;Shi SH
通讯作者：
Shi SH
影响因子：
5.3
作者：
Maricich, Stephen M.;Xia, Anping;Zoghbi, Huda Y.
通讯作者：
Zoghbi, Huda Y.
影响因子：
2.8
作者：
Cramer, KS
通讯作者：
Cramer, KS
影响因子：
2.5
作者：
Duncan, Luke J.;Mangiardi, Dominic A.;Cotanche, Douglas A.
通讯作者：
Cotanche, Douglas A.
影响因子：
2.5
作者：
BROWNER, RH;BARUCH, A
通讯作者：
BARUCH, A