SEX-DEPENDENT LOSS OF PROJECTION NEURONS INVOLVED IN AVIAN SONG LEARNING
SEX-DEPENDENT LOSS OF PROJECTION NEURONS INVOLVED IN AVIAN SONG LEARNING
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DOI：
10.1002/neu.480230606
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发表时间：
1992-08-01
期刊：
影响因子：
--
通讯作者：
NORDEEN, KW
中科院分区：
文献类型：
--
作者：
NORDEEN, EJ;GRACE, A;NORDEEN, KW
在斑胸草雀中，只有雄性会唱歌，而控制歌声的神经区域在神经元数量上表现出明显的性别差异。为了了解性别分化是如何调节一个鸣唱核--新纹状体前部外侧大细胞核（lateral magnocellular nucleus of the anterior neostriatum，IMAN）内神经元数量的，我们研究了投射到原纹状体健壮核（robust nucleus of the archistriatum，RA）的IMAN神经元的性别差异。IMAN与歌曲学习有关，先前的个体发育研究表明，在幼年歌曲学习期间，雄性失去了超过50%的IMAN神经元。根据IMAN内雄激素积累程度及其在Nissl染色组织中的外观的发育变化，推测年轻女性的IMAN神经元损失更大，导致神经元数量的性别差异。然而，这一假设尚未得到直接检验，因为IMAN的Nissl染色边界在幼年动物中有时是模糊的，在成年雌性动物中根本不明显。为了避免这些问题，我们采用逆行示踪剂快蓝研究IMAN神经元的发展定义的基础上，他们的预测RA。我们发现成年雄性的IMAN-RA投射神经元的数量比雌性的多得多，并且这种性别差异在性分化和歌曲学习的幼年期发展，因为雌性中大量的这些神经元丢失，而雄性中没有。关于性分化，我们的结论是，男性化（这是刺激的激素雌二醇）促进保留IMAN-RA投射神经元。此外，我们的研究结果表明，任何损失的IMAN神经元，可能发生在年轻男性不包括细胞投射到RA。
In zebra finches, only males sing, and the neural regions controlling song exhibit prominent, hormone-induced sex differences in neuron number. In order to understand how sexual differentiation regulates neuron number within one song nucleus, the lateral magnocellular nucleus of the anterior neostriatum (IMAN), We studied the development of sex differences among IMAN neurons that project to the robust nucleus of the archistriatum (RA). The IMAN is implicated in song learning, and previous ontogenetic studies have indicated that males lose over 50% of their IMAN neurons during the juvenile song learning period. Based on developmental changes in both the extent of androgen accumulation within the IMAN and its appearance in Nissl-stained tissue, it had been hypothesized that IMAN neuron loss was even greater in young females, resulting in sex differences in neuron number. However, this hypothesis has not been tested directly because the Nissl-stained boundaries of the IMAN sometimes are ambiguous in young animals, and are not evident at all in adult females. To circumvent these problems, we employed the retrograde tracer fast blue to study the development of IMAN neurons defined on the basis of their projections to the RA. we find that the number of these IMAN-RA projection neurons is much greater in adult males than in females, and that this sex difference develops during the juvenile period of sexual differentiation and song learning because a significant number of these neurons are lost in females but not in males. With respect to sexual differentiation, we conclude that masculinization (which is stimulated by the hormone estradiol) promotes the retention of IMAN-RA projection neurons. In addition, our results indicate that any loss of IMAN neurons that may occur in young males does not include cells projecting to the RA.