Department of Psychology and Center for Neuroscience Research, University at Albany-State University of New York, Albany, NY 12222, USA.
Cereb Cortex. 2010 May;20(5):1046-52. doi: 10.1093/cercor/bhp165. Epub 2009 Aug 14.
The progesterone receptor (PR) is transiently expressed in the rat cortex during development and its expression is initiated in the developmentally critical layer, the subplate. As subplate neurons pioneer thalamocortical and corticofugal connectivity, the expression of PR in this layer suggests an important function for PR in cortical development. Using immunocytochemistry for PR, the present study determined the precise ontogeny of PR expression in subplate neurons. The number of cells containing PR immunoreactivity (PRir) within the subplate was quantified from embryonic day (E) 17 through postnatal day (P) 14. The subplate was positively identified by the marker calretinin and by BrDU birthdating. The results demonstrate that PRir is undetectable in fetal cortex on E17, but is first observed in the subplate on E18. The number of PRir cells peaks on P2 and then steadily declines, until PRir is once again not detectable in subplate by P14. This developmental window of PR expression within the subplate coincides with establishment of early cortical circuitry and the gradual demise of subplate cells, suggesting that PR may play a critical role in mediating these fundamental developmental processes.
孕激素受体（PR）在大鼠皮质发育过程中短暂表达，其表达起始于发育关键层——基板。由于基板神经元开拓了丘脑皮质和皮质传出的连接，该层 PR 的表达表明 PR 在皮质发育中具有重要功能。本研究通过孕激素受体免疫细胞化学，确定了基板神经元中 PR 表达的精确发育过程。从胚胎期 17 天（E）到出生后 14 天（P），对基板中含有孕激素受体免疫反应性（PRir）的细胞数量进行了量化。基板通过钙结合蛋白和 BrDU 标记物来进行明确鉴定。结果表明，E17 时胎儿皮质中无法检测到 PRir，但 E18 时首次在基板中观察到 PRir。PRir 细胞数量在 P2 时达到峰值，然后稳定下降，直到 P14 时基板中再次无法检测到 PRir。基板中 PR 表达的这种发育窗口与早期皮质回路的建立和基板细胞的逐渐消失相吻合，表明 PR 可能在调节这些基本发育过程中发挥关键作用。
