Acarin L, González B, Castellano B, Castro A J
Department of Cell Biology, Neurobiology and Anatomy, Stritch School of Medicine, Loyola University at Chicago, Maywood, Illinois 60153, USA.
Exp Neurol. 1997 Oct;147(2):410-7. doi: 10.1006/exnr.1997.6593.
This study was designed to quantify the microglial response following an injection of N-methyl-D-aspartate (NMDA) into the sensorimotor cortex of 6-day-old rats. After survival times ranging from 10 h to 28 days, cryostat sections were processed for the demonstration of microglial cells by means of tomato lectin histochemistry. The injection of NMDA caused an extensive primary lesion involving the neocortex, the rostral hippocampus, and rostral thalamus. In addition, secondary retrograde/anterograde degeneration was also observed in the ventrobasal (VB) complex of the thalamus. Microglial reactivity was already present at 10 h postlesion and restricted to areas of neuronal degeneration. Quantitative analysis was performed on digitized images using NIH Image software and a Macintosh computer. The method is based on densitometric ratios, referred to as the "reactivity grade," between the ipsilateral lesion side and the contralateral control side. Measurements were made to determine a possible increase in the number of microglial cells as well as an increase in lectin binding. The analysis showed that microglial reactivity in areas of primary degeneration peaked at 3 days postlesion, when it was significantly (P < 0.01) higher in comparison to saline-injected litter mates. Microglial response in the cerebral neocortex, showing the highest reactivity grade, as well as in other areas of primary degeneration, returned to control levels by Day 7. Microglial response in the VB complex also peaked at Day 3 (P < 0.05) but maintained this level of reactivity until 7 days postlesion (P < 0.01).
本研究旨在量化向6日龄大鼠的感觉运动皮层注射N-甲基-D-天冬氨酸（NMDA）后小胶质细胞的反应。在10小时至28天的存活期后，通过番茄凝集素组织化学法对低温恒温器切片进行处理，以显示小胶质细胞。注射NMDA导致广泛的原发性损伤，累及新皮层、喙侧海马和喙侧丘脑。此外，在丘脑腹基底（VB）复合体中也观察到继发性逆行/顺行变性。损伤后10小时即出现小胶质细胞反应性，且局限于神经元变性区域。使用NIH Image软件和苹果电脑对数字化图像进行定量分析。该方法基于同侧损伤侧与对侧对照侧之间的光密度比，称为“反应性等级”。进行测量以确定小胶质细胞数量的可能增加以及凝集素结合的增加。分析表明，原发性变性区域的小胶质细胞反应性在损伤后3天达到峰值，此时与注射生理盐水的同窝仔鼠相比显著更高（P<0.01）。大脑新皮层以及其他原发性变性区域的小胶质细胞反应，显示出最高的反应性等级，到第7天时恢复到对照水平。VB复合体中的小胶质细胞反应也在第3天达到峰值（P<0.05），但在损伤后7天一直保持这种反应水平（P<0.01）。
