White matter interstitial neurons (WMIN) are a subset of cortical neurons located in the subcortical white matter. Although they were fist described over 150 years ago, they are still largely unexplored and often considered a small, functionally insignificant neuronal population. WMIN are adult remnants of neurons located in the transient fetal subplate zone (SP). Following development, some of the SP neurons undergo apoptosis, and the remaining neurons are incorporated in the adult white matter as WMIN. In the adult human brain, WMIN are quite a large population of neurons comprising at least 3% of all cortical neurons (between 600 and 1100 million neurons). They include many of the morphological neuronal types that can be found in the overlying cerebral cortex. Furthermore, the phenotypic and molecular diversity of WMIN is similar to that of the overlying cortical neurons, expressing many glutamatergic and GABAergic biomarkers. WMIN are often considered a functionally unimportant subset of neurons. However, upon closer inspection of the scientific literature, it has been shown that WMIN are integrated in the cortical circuitry and that they exhibit diverse electrophysiological properties, send and receive axons from the cortex, and have active synaptic contacts. Based on these data, we are able to enumerate some of the potential WMIN roles, such as the control of the cerebral blood flow, sleep regulation, and the control of information flow through the cerebral cortex. Also, there is a number of studies indicating the involvement of WMIN in the pathophysiology of many brain disorders such as epilepsy, schizophrenia, Alzheimer’s disease, etc. All of these data indicate that WMIN are a large population with an important function in the adult brain. Further investigation of WMIN could provide us with novel data crucial for an improved elucidation of the pathophysiology of many brain disorders. In this review, we provide an overview of the current WMIN literature, with an emphasis on studies conducted on the human brain.

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成年人脑中的白色物质间质神经元：3％的皮质神经元寻求识别

白质间质神经元（WMIN）是位于皮层下白质中的皮质神经元的子集。尽管他们在150年前就被拳头描述过，但在很大程度上还没有被探索，通常被认为是一个很小的，功能上无关紧要的神经元人群。WMIN是位于瞬时胎儿亚板区（SP）的神经元的成人残余物。发育后，一些SP神经元发生凋亡，其余的神经元以WMIN的形式掺入成人白质中。在成人的大脑中，WMIN是相当大的神经元群体，至少占所有皮层神经元的3％（600到1100百万个神经元之间）。它们包括在上层大脑皮层中可以找到的许多形态神经元类型。此外，WMIN的表型和分子多样性类似于其上皮神经元的表达，并表达许多谷氨酸和GABA能生物标记。WMIN通常被认为是神经元在功能上不重要的子集。但是，在对科学文献进行仔细检查后，发现WMIN集成在皮质电路中，并且它们表现出多种电生理特性，可以从皮质发送和接收轴突，并且具有活跃的突触接触。基于这些数据，我们能够列举一些潜在的WMIN作用，例如控制脑血流量，睡眠调节以及控制通过大脑皮质的信息流。另外，有许多研究表明WMIN参与了许多脑部疾病（例如癫痫，精神分裂症，所有这些数据表明，WMIN是在成年大脑中具有重要功能的大量人群。对WMIN的进一步研究可以为我们提供新颖的数据，这些数据对于改善许多脑部疾病的病理生理学至关重要。在本文中，我们概述了当前的WMIN文献，重点是对人脑的研究。