Jahnke Sani, Bedi Kuldip S
School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
Brain Res. 2007 Apr 27;1143:60-9. doi: 10.1016/j.brainres.2007.01.109. Epub 2007 Feb 2.
We have previously shown that undernutrition during early life causes a permanent deficit in the total number of dentate granule cells. However, it is unknown whether this deficit is due to neuronal cell death and/or to fewer cells being born during the period of neurogenesis. We have therefore used stereological methods combined with specific labeling techniques to examine the numbers of apoptotic cells in specific regions of the hippocampal formation. Rats were undernourished by restricting their daily food intake to about half that eaten by well-fed controls. Control and undernourished rats were killed on postnatal day 21, and their brains fixed in 4% paraformaldehyde. Serial sections through the hippocampal formation were labeled with the TUNEL technique to distinguish apoptotic cells. All care and animal handling procedures were approved by the institutional Animal Ethics Committee in line with Australian NHMRC procedures. There were about 21,500 and 57,000 TUNEL-positive cells in the dentate gyrus granule cell layer of control and undernourished rats, respectively. The difference between these values was statistically significant. In the CA3+CA2 region, there were about 22,000 and 19,500 TUNEL-positive cells in control and undernourished rats, respectively. The difference between these values was not statistically significant. Furthermore, it was observed that the majority of the TUNEL-positive cells in the dentate gyrus were located close to the border between the dentate gyrus granule cells and hilus of the hippocampal formation. Our results show that undernutrition during gestation and lactation can result in an increase in the level of TUNEL-positive apoptotic cells in the rat dentate gyrus.
我们之前已经表明，生命早期的营养不良会导致齿状颗粒细胞总数永久性减少。然而，尚不清楚这种减少是由于神经元细胞死亡和/或在神经发生期间产生的细胞较少所致。因此，我们使用了体视学方法结合特定的标记技术来检查海马结构特定区域的凋亡细胞数量。通过将大鼠的每日食物摄入量限制在正常喂养对照组的一半左右来使其营养不良。对照组和营养不良的大鼠在出生后第21天处死，其大脑固定在4%多聚甲醛中。通过TUNEL技术对海马结构的连续切片进行标记以区分凋亡细胞。所有的护理和动物处理程序均符合澳大利亚国家卫生与医学研究委员会的程序，并得到了机构动物伦理委员会的批准。在对照组和营养不良大鼠的齿状回颗粒细胞层中，分别约有21,500个和57,000个TUNEL阳性细胞。这些数值之间的差异具有统计学意义。在CA3+CA2区域，对照组和营养不良大鼠中分别约有22,000个和19,500个TUNEL阳性细胞。这些数值之间的差异无统计学意义。此外，观察到齿状回中大多数TUNEL阳性细胞位于齿状回颗粒细胞与海马结构门之间的边界附近。我们的结果表明，妊娠和哺乳期的营养不良可导致大鼠齿状回中TUNEL阳性凋亡细胞水平增加。
