Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06520, USA.
Cereb Cortex. 2011 Jun;21(6):1231-45. doi: 10.1093/cercor/bhq199. Epub 2010 Nov 1.
The piriform cortex (PCX) is a trilaminar paleocortex that is of interest for its role in odor coding and as a model for studying general principles of cortical sensory processing. While the structure of the mature PCX has been well characterized, its development is poorly understood. Notably, the kinetics as well as the cellular and morphological basis of the postnatal events that shape the PCX remain unknown. We followed the cellular fates of early- versus late-born cells in layer II of the anterior PCX, with a focus on the molecular maturation of pyramidal cells and the kinetics of their differentiation. We showed that: 1) early-born pyramidal cells differentiate more rapidly than late-born cells and 2) the position of pyramidal cells within the thickness of layer II determines the kinetics of their molecular maturation. We then examined the postnatal development of cortical lamination and showed that the establishment of inhibitory networks in the PCX proceeds through an increase in the density of inhibitory synapses despite a decrease in the number of interneurons. Together, our results provide a more comprehensive view of the postnatal development of the anterior PCX and reveal both similarities and differences in the development of this paleocortex versus the neocortex.
梨状皮层（PCX）是一种三层的古皮层，因其在气味编码中的作用以及作为研究皮质感觉处理一般原理的模型而受到关注。虽然成熟 PCX 的结构已经得到很好的描述，但它的发育仍知之甚少。值得注意的是，塑造 PCX 的产后事件的动力学以及细胞和形态学基础仍然未知。我们追踪了前 PCX 层 II 中早期和晚期出生细胞的细胞命运，重点研究了锥体细胞的分子成熟和分化动力学。我们表明：1）早期出生的锥体细胞比晚期出生的细胞分化得更快，2）锥体细胞在层 II 厚度内的位置决定了它们的分子成熟动力学。然后，我们检查了皮质层形成的产后发育，并表明尽管中间神经元数量减少，但 PCX 中抑制性网络的建立是通过增加抑制性突触密度来实现的。总之，我们的研究结果提供了对前 PCX 产后发育的更全面的了解，并揭示了这个古皮层与新皮层在发育上的相似性和差异性。
