前额叶在老年阶段的可塑性及相关机制

大量研究表明, 前额叶的结构和功能更容易受年老化影响; 然而, 近年来的研究发现, 前额叶的结构和功能在老年阶段具有一定的可塑性。对老年人进行认知训练, 能够延缓前额叶皮层厚度的萎缩, 提高白质完整性, 改善神经网络的功能连接和分化, 并可能通过调节多巴胺系统的活动改变前额叶皮质和皮质下结构的功能激活模式。有氧锻炼能够改善心脑血管功能, 保护和促进神经元的存活和生长, 引起前额叶灰质、白质体积的增加及功能激活的变化。认知训练与有氧锻炼等相结合的整合性训练不仅引起前额叶及相关认知功能的改变, 而且具有更好的生态学效度, 使老年人日常认知能力和生活质量得到提高。未来研究应采用多种技术手段, 从多个层面理解老年阶段前额叶的可塑性及相关机制; 加强对与前额叶关系密切的多种认知功能可塑性神经机制的研究; 并重视与整合性训练有关的前额叶可塑性。

Plasticity of the prefrontal cortex in old age and underlying mechanisms

Previous studies have shown that structure and function of the prefrontal cortex (PFC) are particularly vulnerable to aging. On the other hand, recent studies have also indicated that the structural and functional plasticity of PFC is preserved in old age. For older adults, cognitive training attenuates reduction of cortical thickness in PFC, increases white matter integrity, improves intra- and inter-network functional connectivity, and also changes functional activation through modulation of dopamine activity in PFC and subcortical structures. Aerobic exercise improves cardiovascular fitness, preserves neuronal integrity and promotes neurogenesis, which would then lead to increased volumes in prefrontal gray and white matter, and altered functional activation patterns. Multimodal intervention, which combines cognitive training and physical exercise, has demonstrated better ecological validity, enhancing everyday cognition and life quality of older adults. We suggest that future studies should adopt various techniques, in order to better understand the prefrontal neuroplasticity in old age and its related mechanisms; separately analyze the various PFC related cognitive abilities; and lay stress on the more ecological multimodal intervention.