Performance-related increases in hippocampal N-acetylaspartate (NAA) induced by spatial navigation training are restricted to BDNF Val homozygotes.
Recent evidence indicates experience-dependent brain volume changes in humans, but the functional and histological nature of such changes is unknown. Here, we report that adult men performing a cognitively demanding spatial navigation task every other day over 4 months display increases in hippocampal N-acetylaspartate (NAA) as measured with magnetic resonance spectroscopy. Unlike measures of brain volume, changes in NAA are sensitive to metabolic and functional aspects of neural and glia tissue and unlikely to reflect changes in microvasculature. Training-induced changes in NAA were, however, absent in carriers of the Met substitution in the brain-derived neurotrophic factor (BDNF) gene, which is known to reduce activity-dependent secretion of BDNF. Among BDNF Val homozygotes, increases in NAA were strongly related to the degree of practice-related improvement in navigation performance and normalized to pretraining levels 4 months after the last training session. We conclude that changes in demands on spatial navigation can alter hippocampal NAA concentrations, confirming epidemiological studies suggesting that mental experience may have direct effects on neural integrity and cognitive performance. BDNF genotype moderates these plastic changes, in line with the contention that gene-context interactions shape the ontogeny of complex phenotypes.
Center for Lifespan Psychology, Max Planck Institute for Human Development, Lentzeallee 94, Berlin, Germany. loevden@mpib-berlin.mpg.de
Martin
M
Lövdén
Sabine
S
Schaefer
Hannes
H
Noack
Martin
M
Kanowski
Jörn
J
Kaufmann
Claus
C
Tempelmann
Nils Christian
NC
Bodammer
Simone
S
Kühn
Hans-Jochen
HJ
Heinze
Ulman
U
Lindenberger
Emrah
E
Düzel
Lars
L
Bäckman
D000328:Adult; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001931:Brain Mapping; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D005260:Female; D007839:Functional Laterality; D005838:Genotype; D006624:Hippocampus / Q000378:metabolism*; D006720:Homozygote; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012737:Sex Factors; D013037:Spatial Behavior / Q000502:physiology*; D013663:Teaching / Q000379:methods*; D014633:Valine / Q000235:genetics*; D055815:Young Adult
D019208:Brain-Derived Neurotrophic Factor; D001224:Aspartic Acid; C000179:N-acetylaspartate; D014633:Valine