Selective asymmetry in a conserved forebrain to midbrain projection.
Selective asymmetry in a conserved forebrain to midbrain projection.
复制标题
保守的前脑到中脑投射的选择性不对称。
DOI：
10.1002/jez.b.21184
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Halpern,MarnieE
中科院分区：
文献类型：
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作者：
Kuan,Yung-Shu;Gamse,JoshuaT;Schreiber,AlexanderM;Halpern,MarnieE
大脑的左侧和右侧如何获得解剖和功能的专门化尚不清楚。斑马鱼已被证明是探索前脑发育中神经解剖学不对称遗传基础的有用模型。背侧间脑或上丘脑由不对称的松果体复合体和相邻的成对核、左右内侧缰核组成，在斑马鱼幼虫中，它们在大小、神经纤维密度和基因表达模式方面表现出差异。在所有脊椎动物中，来自内侧缰核的轴突在突出的纤维束（反屈束）内投射到共享的中脑目标，即腹侧被盖的脚间核。然而，在斑马鱼中，左侧缰核的投射支配目标核的背侧和腹侧区域，而右侧缰核传出神经仅投射到腹侧区域。在另一种硬骨鱼物种——高度衍生的南方比目鱼——Paralichthys lethostima中也发现了类似的背腹侧缰核连接差异。在这种比目鱼中，缰核投影的方向不对称性似乎与个体变态后采取的左右形态和方向无关。对蝾螈、青蛙和小鼠大脑的比较顺行标记表明，从左右内侧缰核发出的轴突不会投射到不同的区域，而是以互补的镜像模式穿过目标核。因此，尽管缰核-脚间传导系统在脊椎动物大脑中高度保守，但左右连接的刻板背腹地形似乎是硬骨鱼特有的特征。过期。动物园。 (Mol. Dev. Evol.) 308B:669–678, 2007。© 2007 Wiley-Liss, Inc.
How the left and right sides of the brain acquire anatomical and functional specializations is not well understood. The zebrafish has proven to be a useful model to explore the genetic basis of neuroanatomical asymmetry in the developing forebrain. The dorsal diencephalon or epithalamus consists of the asymmetric pineal complex and adjacent paired nuclei, the left and right medial habenulae, which in zebrafish larvae, exhibit differences in their size, neuropil density and patterns of gene expression. In all vertebrates, axons from the medial habenular nuclei project within a prominent fiber bundle, the fasciculus retroflexus, to a shared midbrain target, the interpeduncular nucleus of the ventral tegmentum. However, in zebrafish, projections from the left habenula innervate the dorsal and ventral regions of the target nucleus, whereas right habenular efferents project only to the ventral region. A similar dorsoventral difference in habenular connectivity is found in another teleost species, the highly derived southern flounder,Paralichthys lethostima. In this flatfish, directional asymmetry of the habenular projection appears to be independent of the left–right morphology and orientation that an individual adopts post‐metamorphosis. Comparative anterograde labeling of the brains of salamanders, frogs and mice reveals that axons emanating from the left and right medial habenulae do not project to different domains, but rather, they traverse the target nucleus in a complementary mirror image pattern. Thus, although the habenulo‐interpeduncular conduction system is highly conserved in the vertebrate brain, the stereotypic dorsoventral topography of left–right connections appears to be a feature that is specific to teleosts.J. Exp. Zool. (Mol. Dev. Evol.) 308B:669–678, 2007. © 2007 Wiley‐Liss, Inc.