Physical activity and memory functions: Are neurotrophins and cerebral gray matter volume the missing link?

• Published in: NeuroImage (Orlando, Fla.) Vol. 49; no. 3; pp. 2756 - 2763
• Main Authors: Flöel, A., Ruscheweyh, R., Krüger, K., Willemer, C., Winter, B., Völker, K., Lohmann, H., Zitzmann, M., Mooren, F., Breitenstein, C., Knecht, S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2010; Elsevier Limited
• Subjects: Aged; BDNF; Brain - anatomy & histology; Brain - physiology; Brain-derived neurotrophic factor; Brain-Derived Neurotrophic Factor - blood; Cognition; Cognitive ability; Enzyme-Linked Immunosorbent Assay; Exercise; G-CSF; Granulocyte Colony-Stimulating Factor - blood; Humans; Image Interpretation, Computer-Assisted; Magnetic Resonance Imaging; Memory; Memory - physiology; Middle Aged; Motor Activity - physiology; Nerve Growth Factors - blood; Nerve Growth Factors - metabolism; Neuropsychological Tests; Older people; Physical fitness; Physical Fitness - physiology; Questionnaires; Studies; Surveys and Questionnaires; Verbal learning; Cognition; Exercise; BDNF; G-CSF
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2009.10.043

Epidemiological studies reveal better cognitive function in physically active individuals. Possible mediators for this effect are neurotrophins, which are up-regulated through physical exercise and induce neuronal growth and synaptogenesis in the animal model. Here we cross-sectionally assessed 75 healthy older individuals for levels of physical activity, aerobic fitness, and memory encoding, as well as neurotrophin levels and cerebral gray matter volume. We found that physical activity, but not cardiovascular fitness, was associated with better memory encoding after controlling for age, sex, education, depression, alcohol consumption, and smoking. Higher levels of physical activity were associated with higher levels of the neurotrophin granulocyte colony stimulating factor (G-CSF) and increased cerebral gray matter volume in prefrontal and cingulate cortex as assessed by magnetic resonance voxel-based morphometry. While mediating factors will need to be further elucidated, these findings indicate that even low-level physical activity exerts beneficial effects on memory functions in older individuals.