ION-SELECTIVE MICROELECTRODES AND DIFFUSION MEASUREMENTS AS TOOLS TO EXPLORE THE BRAIN-CELL MICROENVIRONMENT
ION-SELECTIVE MICROELECTRODES AND DIFFUSION MEASUREMENTS AS TOOLS TO EXPLORE THE BRAIN-CELL MICROENVIRONMENT
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DOI：
10.1016/0165-0270(93)90092-6
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发表时间：
1993-07-01
影响因子：
3
通讯作者：
NICHOLSON, C
中科院分区：
文献类型：
--
作者：
NICHOLSON, C
脑细胞微环境的概念已经在至少三个出版物（施密特和萨姆森，1969年;尼科尔森，1980年; Cserr，1986年）和最近的研讨会（Fuxe和Agnati，1991年）更新的概念下的体积传输的主题。我们目前的想法可以概括如下。脑细胞微环境由细胞外空间、浸润该空间的化学介质以及长链糖胺聚糖、蛋白聚糖和糖蛋白组成，所述糖胺聚糖、蛋白聚糖和糖蛋白系在膜上但延伸到空间中。细胞外空间是细胞膜之间的狭窄间隙，可以设想为具有类似于肥皂泡聚集体的肥皂相的几何形状。神经胶质细胞是神经元微环境的一部分，但当我们谈到脑细胞微环境时，我们将其视为排除两种细胞类型的环境。血脑屏障通常包含在脑细胞微环境中，因为它在维持浴介质的组成中起关键作用，并且是脑细胞和神经元微环境的合法部分，但它不是细胞外空间的一部分。脑的细胞外空间是代谢物转移和细胞间化学信号传递的主要通道。此外，它还提供了细胞元件之间的基本隔离。细胞外空间的浸浴介质的典型化学组成近似于人脑脊液组成（Kee和Wood，1987，基于Milhorat的工作）：（浓度以mM计）Na，141; K，3.3; Ca，1.3; Mg，1.2; Cl，124; HCO 3，21;葡萄糖，3.4;尿素，5;磷酸盐，0.48。当用作人工洗浴介质时，通常用95%O2/5%CO2充气以建立约7.4的pH。最近的一本书（Boulton等人，1988）描述了一些适用于微环境研究的方法。
The concept of the brain cell microenvironment has been elaborated in at least three publications (Schmitt and Samson, 1969; Nicholson, 1980; Cserr, 1986) and a recent symposium (Fuxe and Agnati, 1991) updates the concept under the topic of volume transmission. Our present ideas can be summarized as follows. The brain cell microenvironment consists of the extracellular space, the chemical medium that bathes this space, and the long-chain glycosaminoglycans, proteoglycans and glycoproteins that are tethered to membranes but extend into the space. The extracellular space is the narrow interstitium between cell membranes and can be envisaged as having a geometry something like the soap phase of an aggregate of soap bubbles. Glial cells are part of the neuronal microenvironment, but when we speak of the brain cell microenvironment we perceive it as the milieu that excludes both cell types. The blood-brain barrier is often included in the brain cell microenvironment since it plays a crucial role in maintaining the composition of the bathing medium and is legitimately part of the brain cell and neuronal microenvironment but it is not part of the extracellular space. The extracellular space of the brain is a major channel for the transfer of metabolites and for the transmission of chemical signals between cells. In addition, it provides essential isolation between cellular elements. Typical chemical composition of the bathing medium of the extraeellular space is approximated by human cerebrospinal fluid composition (Kee and Wood, I987, based on work by Milhorat):(concentrations in raM) Na, 141; K, 3.3; Ca, 1.3; Mg, 1.2; CI, 124; HCO3, 21; glucose, 3.4; urea, 5; phosphate, 0.48. When used as an artificial bathing medium it is usually gassed with 95% 02/5% CO 2 to establish a pH of about 7.4. A recent book (Boulton et al., 1988) describes some methods applicable to the study of the microenvironment.