Cadete-Leite A, Alves M C, Tavares M A, Paula-Barbosa M M
Department of Anatomy, Porto Medical School, Portugal.
Alcohol. 1990 Mar-Apr;7(2):145-52. doi: 10.1016/0741-8329(90)90076-o.
Previous studies demonstrated that alcohol induces marked deterioration of the cerebral cortex. However, quantitative evaluations of neurons and synapses of the prefrontal cortex from chronic alcohol-fed and withdrawn animals are nonexistent, in spite of the functional implications that can underlie structural changes in this cortical area. To achieve this evaluation, we used groups of rats alcohol-fed for 6, 12 and 18 months, their respective controls as well as groups of rats alcohol-fed for 6 and 12 months and then switched to water for 6 months--withdrawal groups. The thickness of the prelimbic cortical layers I-III was reduced in the alcohol-fed and withdrawal groups. A significant reduction in the density of cells was found, which was more marked after withdrawal. Conversely, the density of synapses increased after alcohol exposure and withdrawal; such numerical shifts lead to a significant increase in the synapse-to-neuron ratio. These results indicate that the cortical circuitry of the prelimbic cortex is vulnerable to prolonged periods of alcohol exposure and withdrawal and allow to advance the view that the alterations can induce functional implications.
先前的研究表明，酒精会导致大脑皮层显著退化。然而，尽管前额叶皮层结构变化可能具有功能意义，但目前尚无对长期摄入酒精及戒断后的动物前额叶皮层神经元和突触的定量评估。为了进行这种评估，我们使用了分别经6个月、12个月和18个月酒精喂养的大鼠组、它们各自的对照组，以及先经6个月和12个月酒精喂养、然后改为饮水6个月的大鼠组——戒断组。在酒精喂养组和戒断组中，前边缘皮层I - III层的厚度有所减小。发现细胞密度显著降低，戒断后更为明显。相反，酒精暴露和戒断后突触密度增加；这种数量上的变化导致突触与神经元的比例显著增加。这些结果表明，前边缘皮层的皮质回路易受长期酒精暴露和戒断的影响，并支持这样一种观点，即这些改变可能会引发功能方面的影响。
