Bertoni-Freddari C, Giuli C, Pieri C, Paci D
Brain Res. 1986 Feb 26;366(1-2):187-92. doi: 10.1016/0006-8993(86)91294-1.
The morphological plasticity of synaptic junctions was investigated by means of quantitative stereology in the dentate gyrus supragranular layer of young (3 months), adult (12 months) and old (30 months) female Fisher 344 rats. The numerical (Nv) and surface (Sv) density and the average surface area (S) of EPTA-stained synaptic junctions were calculated on 100 EM pictures per age group. We found that Nv significantly increased between the young and adult group and decreased in old animals when compared both to 3 and 12 months of age. Sv was unchanged in young and adult rats, whereas it underwent a significant reduction in the old group. The percentage distribution of S showed that at 3 months of age the majority of the synaptic population had an average size ranging between 0.12 and 0.20 micron 2, whereas during adulthood and aging there was a shift towards smaller and larger synaptic contacts, respectively. Taking into account Nv, Sv and S all together per age group, the present findings demonstrate that the morphological aspect of synaptic plasticity is markedly influenced by time and that during aging it undergoes a serious impairment. The possible involvement in memory and learning processes of these synaptic age-related morphological adaptations and the fact that the investigated junctions are supposed to be cholinergic is discussed.
通过定量体视学方法，研究了幼年（3个月）、成年（12个月）和老年（30个月）雌性Fisher 344大鼠齿状回颗粒上层突触连接的形态可塑性。计算每个年龄组100张电子显微镜图片上经EPTA染色的突触连接的数量密度（Nv）、表面积密度（Sv）和平均表面积（S）。我们发现，与3个月和12个月龄的大鼠相比，幼年组和成年组之间Nv显著增加，而老年动物的Nv则下降。幼年和成年大鼠的Sv没有变化，而老年组的Sv则显著降低。S的百分比分布表明，3个月龄时，大多数突触群体的平均大小在0.12至0.20平方微米之间，而在成年期和衰老过程中，突触接触分别向更小和更大的方向转变。综合考虑每个年龄组的Nv、Sv和S，目前的研究结果表明，突触可塑性的形态方面受到时间的显著影响，并且在衰老过程中会受到严重损害。讨论了这些与年龄相关的突触形态适应可能参与记忆和学习过程，以及所研究的突触连接被认为是胆碱能的这一事实。
