Institute for Pediatric Regenerative Medicine, University of California at Davis Sacramento, CA, USA ; Medical Pathology and Laboratory Medicine, University of California at Davis Sacramento, CA, USA ; MIND Institute, University of California at Davis Sacramento, CA, USA.
MIND Institute, University of California at Davis Sacramento, CA, USA ; Department of Psychiatry and Behavioral Sciences, University of California at Davis Sacramento, CA, USA.
Front Neuroanat. 2014 Jun 17;8:48. doi: 10.3389/fnana.2014.00048. eCollection 2014.
The marginal zone (MZ) of the prenatal cerebral cortex plays a crucial role in cellular migration and laminar patterning in the developing neocortex and its equivalent in the adult brain - layer I, participates in cortical circuitry integration within the adult neocortex. The MZ/layer I, which has also been called the plexiform layer and cell-poor zone of Meynert, among others, is home to several cell populations including glia, neurons, and Cajal-Retzius (CR) cells. Cajal once said that the MZ is one of the oldest formations in the phylogenetic series, and that the characteristics of layer I in human are similar in all vertebrates except fish (Ramon y Cajal, 1899). Despite the presence of CR cells in the MZ/layer I of all developing and adult vertebrate brains, and more than one hundred years of research, the phenotype and function of layer I cells have still not been clearly defined. Recent technological advances have yielded significant progress in functional and developmental studies, but much remains to be understood about neurons in MZ/layer I. Since the time of Retzius and Cajal, and continuing with modern era research from the likes of Marín-Padilla, the study of CR cells has been based on their morphological characteristics in Golgi staining. However, since Cajal's initial description, the term "CR cell" has been applied differently and now is often used to indicate reelin (Reln)-positive cells in MZ/layer I. Here we review the history of work by Cajal, Retzius, and others pertaining to CR cells. We will establish a link between original descriptions of CR cell morphology by Cajal, Retzius, and others, and current understandings of the cell populations that reside in MZ/layer I based on the use of cellular markers. We propose to use the term "CR cell" for the class of neurons that express Reln in the MZ/layer I in both prenatal, developing and adult cerebral cortex.
产前大脑皮层的边缘区（MZ）在细胞迁移和新皮层的层状模式形成中起着至关重要的作用，其在成人脑中的对应物-第 I 层，参与了成人新皮层皮质电路的整合。MZ/第 I 层，也被称为丛状层和迈内特的细胞稀少区等，是包括神经胶质细胞、神经元和 Cajal-Retzius (CR) 细胞在内的几个细胞群体的所在地。卡哈尔曾经说过，MZ 是系统发生系列中最古老的形成之一，人类第 I 层的特征在除鱼类之外的所有脊椎动物中都是相似的（卡哈尔，1899 年）。尽管所有发育中和成年脊椎动物的大脑的 MZ/第 I 层都存在 CR 细胞，并且已经进行了一百多年的研究，但第 I 层细胞的表型和功能仍未得到明确界定。最近的技术进步在功能和发育研究方面取得了重大进展，但对于 MZ/第 I 层中的神经元仍有许多需要了解的地方。自从 Retzius 和 Cajal 的时代以来，并且在现代时代的研究中，如 Marín-Padilla 的研究，CR 细胞的研究一直基于它们在高尔基染色中的形态特征。然而，自从 Cajal 的最初描述以来，“CR 细胞”一词的应用方式有所不同，现在通常用于表示 MZ/第 I 层中的 reelin (Reln)-阳性细胞。在这里，我们回顾了 Cajal、Retzius 和其他人关于 CR 细胞的工作历史。我们将建立 Cajal、Retzius 和其他人对 CR 细胞形态的原始描述与基于细胞标记物的 MZ/第 I 层中存在的细胞群体的当前理解之间的联系。我们建议将“CR 细胞”一词用于在产前、发育中和成年大脑皮层的 MZ/第 I 层中表达 Reln 的神经元类别。
