Laboratory of Cortical Circuits in Health and Disease, CIPF Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain.
Department of Psychiatry, Neuroscience Program and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94158, USA.
Development. 2020 Jul 22;147(14):dev185033. doi: 10.1242/dev.185033.
Cortical interneurons (CINs) originate in the ganglionic eminences (GEs) and migrate tangentially to the cortex guided by different attractive and repulsive cues. Once inside the cortex, the cellular and molecular mechanisms determining the migration of CINs along the rostrocaudal axis are less well understood. Here, we investigated the cortical distribution of CINs originating in the medial and caudal GEs at different time points. Using molecular and genetic labeling, we showed that, in the mouse, early- and late-born CINs (E12 versus E15) are differentially distributed along the rostrocaudal axis. Specifically, late-born CINs are preferentially enriched in cortical areas closer to their respective sites of origin in the medial or caudal GE. Surprisingly, our experiments failed to show a preferential migration pattern along the rostrocaudal axis for medial- or caudal-born CINs. Moreover, transplantation experiments suggested that the rostrocaudal dispersion of CINs depends on the developmental stage of the host brain and is limited by the migration time and the increasing size of the developing brain. These data suggest that the embryonic expansion of the cortex contributes to the rostrocaudal distribution of CINs.
皮质中间神经元（CINs）起源于神经节隆起（GEs），并在不同的趋化和排斥信号的引导下沿切线方向迁移到皮质。一旦进入皮质，确定 CIN 沿前后轴迁移的细胞和分子机制就不太清楚了。在这里，我们研究了起源于内侧和尾侧 GE 的 CIN 在不同时间点在皮质中的分布。使用分子和遗传标记，我们表明，在小鼠中，早期和晚期出生的 CIN（E12 与 E15）沿前后轴呈不同的分布。具体来说，晚期出生的 CIN 更丰富地分布在靠近它们在内侧或尾侧 GE 中各自起源部位的皮质区域。令人惊讶的是，我们的实验未能显示出内侧或尾侧出生的 CIN 沿前后轴的优先迁移模式。此外，移植实验表明，CIN 的前后扩散取决于宿主大脑的发育阶段，并且受到迁移时间和发育中大脑不断增大的限制。这些数据表明，皮质的胚胎扩张有助于 CIN 的前后分布。
