Sadaka Y, Lev D L, Weinfeld L, White E L
Department of Morphology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Somatosens Mot Res. 2000;17(3):245-54. doi: 10.1080/08990220050117600.
Alterations in the numerical density and structure of asymmetrical synapses were examined in thin sections through barrel D4 in six CD/1 mice, including three controls and three sensory deprived animals. Sensory deprivation was effected by once daily trimming of all large mystacial vibrissae on the contralateral side of the snout from P0. The mice were perfuse-fixed at P20, several days following the termination of rapid synaptic growth during barrel development (White et al., Somatosens Mot Res 14: 34-55, 1997). Cerebral hemispheres contralateral to the deprived side were osmicated, sectioned at 40 microm and embedded in plastic for thin sectioning. Sterio's (J Microsc 134: 127-136, 1984) procedure combined with serial thin section analysis (Braendgaard and Gundersen, J Neurosci Meth 18: 39-78, 1986), was applied blindly to systematic random samples of neuropil in barrel hollows and septa. No significant difference in the numerical density, estimated total number, or in the proportion of perforated postsynaptic densities was observed. However, a significant decrease in the diameters of asymmetrical postsynaptic densities was observed in hollow (P < 0.05) and septal (P < 0.05) neuropil of deprived animals. These results demonstrate a significant morphological alteration in asymmetrical synapses of a type consistent with a reduction in synaptic activity consequent to sensory deprivation.
在六只CD/1小鼠的D4桶状皮层的薄切片中，研究了不对称突触的数量密度和结构变化，其中包括三只对照小鼠和三只感觉剥夺动物。从出生后第0天开始，每天对鼻对侧所有大的触须进行修剪，以实现感觉剥夺。在出生后第20天，即桶状皮层发育过程中快速突触生长结束几天后，对小鼠进行灌注固定（White等人，《躯体感觉与运动研究》14: 34 - 55，1997）。将剥夺侧对侧的大脑半球进行锇酸处理，切成40微米厚的切片，并嵌入塑料中进行薄切片。采用Sterio方法（《显微镜学杂志》134: 127 - 136，1984）结合连续薄切片分析（Braendgaard和Gundersen，《神经科学方法杂志》18: 39 - 78，1986），对桶状皮层空洞和间隔中的神经毡系统随机样本进行盲法分析。在数量密度、估计总数或穿孔突触后致密物比例方面未观察到显著差异。然而，在剥夺动物的空洞（P < 0.05）和间隔（P < 0.05）神经毡中，观察到不对称突触后致密物直径显著减小。这些结果表明，不对称突触存在显著的形态学改变，这种改变与感觉剥夺导致的突触活动减少相一致。
