Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany.
Cell. 2010 Sep 3;142(5):800-9. doi: 10.1016/j.cell.2010.07.043.
The evolution of the highest-order human brain center, the "pallium" or "cortex," remains enigmatic. To elucidate its origins, we set out to identify related brain parts in phylogenetically distant animals, to then unravel common aspects in cellular composition and molecular architecture. Here, we compare vertebrate pallium development to that of the mushroom bodies, sensory-associative brain centers, in an annelid. Using a newly developed protocol for cellular profiling by image registration (PrImR), we obtain a high-resolution gene expression map for the developing annelid brain. Comparison to the vertebrate pallium reveals that the annelid mushroom bodies develop from similar molecular coordinates within a conserved overall molecular brain topology and that their development involves conserved patterning mechanisms and produces conserved neuron types that existed already in the protostome-deuterostome ancestors. These data indicate deep homology of pallium and mushroom bodies and date back the origin of higher brain centers to prebilaterian times.
最高阶人类大脑中枢“大脑皮层”的进化仍然是个谜。为了阐明其起源，我们着手在进化上相距甚远的动物中识别相关的脑区，然后揭示细胞组成和分子结构的共同方面。在这里，我们将脊椎动物大脑皮层的发育与环节动物感觉-联想脑中心的蘑菇体进行比较。使用新开发的基于图像配准的细胞分析方案（PrImR），我们获得了发育中的环节动物大脑的高分辨率基因表达图谱。与脊椎动物大脑皮层的比较表明，环节动物的蘑菇体从相似的分子坐标发育而来，在保守的整体分子大脑拓扑结构中，它们的发育涉及保守的模式形成机制，并产生了在原生动物-后生动物祖先中已经存在的保守神经元类型。这些数据表明大脑皮层和蘑菇体具有很深的同源性，并将高级大脑中枢的起源追溯到原口动物时代。
