Department of Life and Environmental Sciences, Section of Neuroscience and Anthropology, University of Cagliari, Monserrato, 09042, Cagliari, Italy.
Institute of Neuroscience, National Research Council, Monserrato, 09042, Cagliari, Italy.
Neuropharmacology. 2019 Jun;151:45-54. doi: 10.1016/j.neuropharm.2019.03.030. Epub 2019 Mar 29.
Environmental enrichment is known to improve brain plasticity and protect synaptic function from negative insults. In the present study we used the exposure to social enrichment to ameliorate the negative effect observed in post weaning isolated male rats in which neurotrophic factors, neurogenesis, neuronal dendritic trees and spines were altered markedly in the hippocampus. After the 4 weeks of post-weaning social isolation followed by 4 weeks of reunion, different neuronal growth markers as well as neuronal morphology were evaluated using different experimental approaches. Social enrichment restored the reduction of BDNF, NGF and Arc gene expression in the whole hippocampus of social isolated rats. This effect was paralleled by an increase in density and morphology of dendritic spines, as well as in neuronal tree arborisation in granule cells of the dentate gyrus. These changes were associated with a marked increase in neuronal proliferation and neurogenesis in the same hippocampal subregion that were reduced by social isolation stress. These results further suggest that the exposure to social enrichment, by abolishing the negative effect of social isolation stress on hippocampal plasticity, may improve neuronal resilience with a beneficial effect on cognitive function.
环境丰富被认为可以改善大脑的可塑性，并保护突触功能免受负面刺激的影响。在本研究中，我们使用社会丰富化的暴露来改善断奶后雄性大鼠在社会隔离后观察到的负面影响，这些大鼠的神经发生、神经元树突和棘突在海马体中发生了明显改变。在断奶后 4 周的社会隔离后，进行了 4 周的团聚，然后使用不同的实验方法评估了不同的神经元生长标志物和神经元形态。社会丰富化恢复了社会隔离大鼠整个海马体中 BDNF、NGF 和 Arc 基因表达的减少。这种效果与树突棘密度和形态的增加以及齿状回颗粒细胞的神经元树突分支化相平行。这些变化与海马体同一亚区神经元增殖和神经发生的显著增加有关，而社会隔离应激会导致这些增加减少。这些结果进一步表明，暴露于社会丰富化可以消除社会隔离应激对海马体可塑性的负面影响，从而提高神经元的弹性，对认知功能产生有益的影响。
