老年性记忆减退大鼠内侧隔核突触结构的改变

取老年记忆减退组 (简称减退组 )、老年记忆正常组 (简称正常组 )和青年组大鼠内侧隔核进行透射电镜观察。证明 :减退组内侧隔核中突触数密度较青年组和正常组分别下降了 45 .2 7%和 44.16% ( P<0 .0 1) ;突触连接带平均面积 :减退组较青年组显著增加 ( P<0 .0 5 ) ;突触连接带面密度 :减退组较青年组和正常组分别下降了 3 5 .2 9和 3 3 .3 3 ( P<0 .0 1) ;突触的体密度 :减退组较青年组和正常组分别下降了 46.98和 49.68 ( P<0 .0 1)。统计结果表明 :受试大鼠的逃避潜伏期与突触数密度、突触连接带面密度、体密度呈明显负相关 ( r=-0 .8943 ,P<0 .0 1;r=-0 .80 0 7,P<0 .0 1;r=-0 .90 17,P<0 .0 1) ;与突触连接带平均面积呈显著正相关 ( r=0 .62 73 ,P<0 .0 5 )。还证明减退组大鼠含线粒体的突触百分比、突触前体内突触小泡数都有大幅度下降 ;正常组的含线粒体突触的百分比、突触小泡数较青年组也有减少。本研究结果提示 :减退组大鼠内侧隔核突触发生退行性变 ,此改变可能是老年性记忆减退的突触学基础

THE CHANGES OF SYNAPTIC STRUCTURE IN SEPTUM MEDIALIS OF SENILE MEMORY DEFICITS RAT

male healthy SD rats, including 20 young(3 months)and 40 old(26 months), were examined with Morris water maze. The mean escape latency of the senile memory deficits rat(SMD) were longer than the mean 2s of the young, whereas in senile memory normal rat(SMN) the mean escape latency was less than the mean 1s of the young. Qualitative and quantitative analysis was carried out for synaptic construction in septum medialis(SM). Numberical density, surface density and volume density of synaptic zones in SM of SMD had a marked reduction than that of SMN and the young. The mean escape latency of examined rats had a significant negative correlation with synapse numberical density, surface density and volume density. Synaptic ribbon area in SM of SMD was increased significantly than the young, but there was no significance between that of SMD and SMN. The mean escape latency of examined rats and synaptic ribbon area had a positive correlation. The percentage of synapse containing mitochondria and the number of vesicles of SMD was decreased as well. The results suggested the synapse in SM of SMD occurred retrograde degeneration, which might be the synaptic mechanism of senile memory deficit.