Lolova I S, Lolov S R, Itzev D E
Institute of Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Mech Ageing Dev. 1997 Sep;97(3):193-205. doi: 10.1016/s0047-6374(97)00062-6.
The morphological appearance and quantitative parameters characterizing the dendrites of NADPH-diaphorase-stained neurons in the laterodorsal (LDT) and pedunculopontine (PPN) tegmental nuclei of 3-, 12- and 26-month-old rats were studied. All dendritic segments were classified according to the number of terminal and link segments they drain and the vertex analysis was used to quantify the dendritic tree and to determine its configuration. Morphological aberrations of the dendrites as local swelling, nodulation, thinning, shrinkage, folding and even the appearance of stumps were observed with advancing age. The quantitative analysis demonstrated a significant reduction (one-way ANOVA) of the total dendritic length, mean terminal path length, maximal segment length, total segment number and number of terminal segments at the rostral two thirds of the LDT and in the PPN. The mean vertex path length and the mean segment length significantly decreased only at the rostral level of the LDT. Plotting of the segment length against equivalent orders showed a decrease in all generations of the dendritic segments. The vertex ratios remained constant and indicated that the configuration of the dendritic tree remained unchanged during aging. The alterations in the dendrites mainly developed after 12 months of age. The age-related changes in the morphology and quantitative parameters of the dendrites in the rostral two thirds of the LDT and PPN were rather similar, which could be explained by the common anatomical, neurochemical and electrophysiological features. Thus, the present results suggest a mild, but continuous regression of the dendritic tree of the rat LDT and PPN in normal aging.
研究了3月龄、12月龄和26月龄大鼠的外侧背盖区（LDT）和脚桥被盖核（PPN）中NADPH-黄递酶染色神经元树突的形态外观和定量参数。根据其引流的终末节段和连接节段的数量对所有树突节段进行分类，并采用顶点分析来量化树突树并确定其形态。随着年龄增长，观察到树突的形态异常，如局部肿胀、结节、变细、萎缩、折叠，甚至出现树突残端。定量分析表明，LDT前三分之二和PPN处的总树突长度、平均终末路径长度、最大节段长度、总节段数和终末节段数显著减少（单因素方差分析）。仅在LDT的头端水平，平均顶点路径长度和平均节段长度显著降低。将节段长度与等效阶数作图显示，所有代的树突节段长度均减少。顶点比率保持恒定，表明树突树的形态在衰老过程中保持不变。树突的改变主要在12月龄后出现。LDT和PPN前三分之二处树突的形态和定量参数的年龄相关变化相当相似，这可以通过共同的解剖学、神经化学和电生理特征来解释。因此，本研究结果表明，在正常衰老过程中，大鼠LDT和PPN的树突树存在轻度但持续的退化。
