Marschner A, Mell T, Wartenburger I, Villringer A, Reischies F M, Heekeren H R
Berlin NeuroImaging Center, Charité, Campus Mitte, Schumannstr. 20/21, 10117 Berlin, Germany.
Brain Res Bull. 2005 Nov 15;67(5):382-90. doi: 10.1016/j.brainresbull.2005.06.010. Epub 2005 Jul 11.
Healthy aging is associated with a number of neuroanatomical and neurobiological alterations that result in various cognitive changes. Both, the dopaminergic as well as the serotonergic system are subject to change during aging. Receptor loss and severe structural changes in PFC and striatum have been reported. Aging is associated with a progressive decline in several cognitive functions, such as episodic memory, working memory, and processing speed. Furthermore, it is associated with deficits in tasks requiring adaptation to external feedback of right or wrong, or task-switching. Here, we develop the hypothesis that this loss of behavioral flexibility is caused by structural and functional alterations of the reward system leading to impairments in reward processing, learning stimulus reinforcement associations, and reward-based decision-making. We review (a) data on neural correlates and substrates of reward processing in young healthy animals and humans, (b) evidence for age related functional and structural alterations of the reward system, and (c) behavioral and neuroimaging data of age effects on reward-based decision-making processes. Implications for neuroeconomics and neurodegenerative diseases are discussed.
健康衰老与一些神经解剖学和神经生物学改变相关，这些改变会导致各种认知变化。多巴胺能系统和5-羟色胺能系统在衰老过程中都会发生变化。据报道，前额叶皮质（PFC）和纹状体存在受体丧失和严重的结构变化。衰老与多种认知功能的逐渐衰退有关，如情景记忆、工作记忆和处理速度。此外，它还与在需要适应正确或错误的外部反馈或任务切换的任务中出现的缺陷有关。在此，我们提出一个假设，即这种行为灵活性的丧失是由奖励系统的结构和功能改变导致的，这些改变会损害奖励处理、学习刺激强化关联和基于奖励的决策。我们回顾了（a）关于年轻健康动物和人类奖励处理的神经相关性和底物的数据，（b）奖励系统与年龄相关的功能和结构改变的证据，以及（c）年龄对基于奖励的决策过程影响的行为和神经影像学数据。还讨论了对神经经济学和神经退行性疾病的影响。
