Cadete-Leite A, Tavares M A, Pacheco M M, Volk B, Paula-Barbosa M M
Department of Anatomy, Porto Medical School, Alameda Hernâni Monteiro, Portugal.
Alcohol. 1989 Jul-Aug;6(4):303-10. doi: 10.1016/0741-8329(89)90087-6.
A quantitative study of the CA3 pyramidal cells and of the mossy fiber-CA3 synapses (MF-CA3) of the rat hippocampal formation was performed in rats alcohol-fed for 6, 12 and 18 months and respective age-matched controls. Additional groups alcohol-fed for 6 and 12 months and withdrawn for 6 months were also studied. The numerical densities of the CA3 pyramids and of the synapses were calculated applying the disector method to adjacent sections of the CA3 pyramidal cell layer and the stratum lucidum respectively. The results showed a progressive loss of pyramidal cells in alcohol-treated and withdrawal groups and a significant decrease of MF-CA3 synapses after 18 months of alcohol feeding. Taking into account that both hippocampal granule and CA3 pyramidal cells are reduced, the maintenance of the relative number of MF-CA3 synapses in 6- and 12-month alcohol-fed rats suggests the formation of new contacts. The increased proportion of the MF plasmalemma occupied by synapses can also be interpreted as an additional compensation process. These data show that MF-CA3 synapses display plastic and degenerative changes after chronic alcohol consumption and withdrawal which presumably will lead to functional modifications of the hippocampal circuitry.
对酒精喂养6个月、12个月和18个月的大鼠以及相应年龄匹配的对照大鼠的海马结构CA3锥体细胞和苔藓纤维-CA3突触（MF-CA3）进行了定量研究。还研究了另外两组分别酒精喂养6个月和12个月后戒断6个月的大鼠。分别对CA3锥体细胞层和透明层的相邻切片应用分割法计算CA3锥体和突触的数值密度。结果显示，酒精处理组和戒断组的锥体细胞逐渐减少，酒精喂养18个月后MF-CA3突触显著减少。考虑到海马颗粒细胞和CA3锥体细胞均减少，6个月和12个月酒精喂养大鼠中MF-CA3突触相对数量的维持表明形成了新的突触联系。突触占据的MF质膜比例增加也可解释为一种额外的代偿过程。这些数据表明，慢性酒精摄入和戒断后，MF-CA3突触表现出可塑性和退行性变化，这可能会导致海马回路的功能改变。
