Maass Anne, Düzel Sandra, Brigadski Tanja, Goerke Monique, Becke Andreas, Sobieray Uwe, Neumann Katja, Lövdén Martin, Lindenberger Ulman, Bäckman Lars, Braun-Dullaeus Rüdiger, Ahrens Dörte, Heinze Hans-Jochen, Müller Notger G, Lessmann Volkmar, Sendtner Michael, Düzel Emrah
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE), Leipziger Str. 44, 39120 Magdeburg, Germany.
Center for Lifespan Psychology, Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany.
Neuroimage. 2016 May 1;131:142-54. doi: 10.1016/j.neuroimage.2015.10.084. Epub 2015 Nov 3.
Animal models point towards a key role of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-I (IGF-I) and vascular endothelial growth factor (VEGF) in mediating exercise-induced structural and functional changes in the hippocampus. Recently, also platelet derived growth factor-C (PDGF-C) has been shown to promote blood vessel growth and neuronal survival. Moreover, reductions of these neurotrophic and angiogenic factors in old age have been related to hippocampal atrophy, decreased vascularization and cognitive decline. In a 3-month aerobic exercise study, forty healthy older humans (60 to 77years) were pseudo-randomly assigned to either an aerobic exercise group (indoor treadmill, n=21) or to a control group (indoor progressive-muscle relaxation/stretching, n=19). As reported recently, we found evidence for fitness-related perfusion changes of the aged human hippocampus that were closely linked to changes in episodic memory function. Here, we test whether peripheral levels of BDNF, IGF-I, VEGF or PDGF-C are related to changes in hippocampal blood flow, volume and memory performance. Growth factor levels were not significantly affected by exercise, and their changes were not related to changes in fitness or perfusion. However, changes in IGF-I levels were positively correlated with hippocampal volume changes (derived by manual volumetry and voxel-based morphometry) and late verbal recall performance, a relationship that seemed to be independent of fitness, perfusion or their changes over time. These preliminary findings link IGF-I levels to hippocampal volume changes and putatively hippocampus-dependent memory changes that seem to occur over time independently of exercise. We discuss methodological shortcomings of our study and potential differences in the temporal dynamics of how IGF-1, VEGF and BDNF may be affected by exercise and to what extent these differences may have led to the negative findings reported here.
动物模型表明，脑源性神经营养因子（BDNF）、胰岛素样生长因子-I（IGF-I）和血管内皮生长因子（VEGF）在介导运动诱导的海马体结构和功能变化中起关键作用。最近，血小板衍生生长因子-C（PDGF-C）也被证明可促进血管生长和神经元存活。此外，老年时这些神经营养和血管生成因子的减少与海马萎缩、血管化降低和认知衰退有关。在一项为期3个月的有氧运动研究中，40名健康老年人（60至77岁）被伪随机分配到有氧运动组（室内跑步机，n = 21）或对照组（室内渐进性肌肉放松/伸展，n = 19）。正如最近报道的那样，我们发现了与老年人海马体与健康相关的灌注变化的证据，这些变化与情景记忆功能的变化密切相关。在这里，我们测试BDNF、IGF-I、VEGF或PDGF-C的外周水平是否与海马体血流量、体积和记忆表现的变化有关。生长因子水平未受到运动的显著影响，其变化与健康或灌注的变化无关。然而，IGF-I水平的变化与海马体体积变化（通过手动容积测量和基于体素的形态测量得出）和后期言语回忆表现呈正相关，这种关系似乎独立于健康、灌注或它们随时间的变化。这些初步发现将IGF-I水平与海马体体积变化以及可能与海马体相关的记忆变化联系起来，这些变化似乎随着时间的推移独立于运动而发生。我们讨论了我们研究的方法学缺点，以及IGF-1、VEGF和BDNF可能受到运动影响的时间动态方面的潜在差异，以及这些差异可能在多大程度上导致了此处报告的负面结果。
