Cellular Growth in Various Regions of the Developing Rat Brain
Cellular Growth in Various Regions of the Developing Rat Brain
复制标题
发育中的大鼠大脑各区域的细胞生长
作者：
I. Fish;M. Winick
浸提液：对6 ~ 22日龄大鼠全脑、大脑、小脑、海马和脑干的细胞生长模式进行了研究。当只测量体重时，不同区域之间的差异很小;然而，当测量细胞数（DNA）或每个细胞的蛋白质（蛋白质：DNA）时，区域差异变得非常显著。在小脑中，DNA含量在6到17天之间增加了8.5倍，随后逐渐减少。在此期间，蛋白质：DNA比率下降。虽然大脑中的细胞数仅增加了2.5倍，但其持续到21天，此时实验终止。10天后，蛋白质：DNA比例也有所增加。在脑干中，细胞数量在6至14天之间适度增加。10天后，蛋白质：DNA比率增加了4倍。在海马，有一个离散的细胞数量增加，只有14和17 day.These数据表明存在不同的区域模式的细胞生长在出生后的成熟rat brain.Speculation：大脑，虽然经常被视为一个独立的器官，是由一些解剖学上不同的区域，执行单独的和独特的功能。该实验室以前的数据表明，整个大鼠大脑的细胞分裂在出生后21天停止，整个人脑的细胞分裂在6个月大时停止。这项研究表明，大鼠大脑的不同区域具有不同的细胞分裂速率，并且细胞生长的整个模式具有区域特异性。由于某些功能是受区域控制的，所以这里描述的区域生长模式可能具有功能相关性。已知环境（营养）的改变会影响整个大脑的细胞分裂速率。环境影响可能因区域而异。通过研究环境刺激（缺氧或营养不良）对区域生长模式的影响，并将这些影响与功能变化相关联，可能将细胞变化与功能缺陷联系起来。
Extract: The cellular growth patterns in whole brain, cerebrum, cerebellum, hippocampus, and brainstem were examined in rats between 6 and 22 days of age. When weight alone was measured, little difference was seen between the various regions; however, when cell number (DNA) or protein per cell (protein: DNA) was measured, regional differences became very striking.In the cerebellum, DNA content increased 8.5 fold between 6 and 17 days and subsequently tapered off. The protein: DNA ratio declined during this period. Although the increase in cell number in the cerebrum was only 2.5 fold, it continued until 21 days, at which time the experiment was terminated. After 10 days there was also an increase in the protein: DNA ratio. In the brainstem, there was a modest increase in cell number between 6 and 14 days. After 10 days the protein: DNA ratio increased 4 fold. In the hippocampus, there was a discrete increase in cell number only between 14 and 17 days.These data demonstrate the existence of distinct regional patterns of cellular growth during postnatal maturation of rat brain.Speculation: The brain, although often viewed as a discrete organ, is composed of a number of anatomically distinct regions that perform separate and unique functions. Previous data from this laboratory have shown that cell division ceases in whole rat brain by 21 days postnatally and in whole human brain by six months of age. This study demonstrates that various regions of rat brain have different rates of cell division and that the entire pattern of cellular growth is regionally specific. Since certain functions are regionally controlled, it is possible that the regional growth patterns described here have functional correlates.Alteration in the environment (nutrition) is known to affect the rate of cell division in whole brain. It is possible that environmental effects may be regionally specific. By studying the effects of environmental stimuli (anoxia or malnutrition) on regional growth patterns and correlating these effects with functional changes, it may be possible to relate cellular changes to functional deficits.