Correlation between serum brain-derived neurotrophic factor level and an in vivo marker of cortical integrity

Background: Brain-derived neurotrophic factor (BDNF) signaling at synapses improves synaptic strengthening associated with learning and memory. In the present study we hypothesized that serum BDNF concentration is associated with in vivo level of cerebral Nacetylaspartate (NAA), a well established marker of neuronal integrity. Methods: In 36 healthy subjects BDNF serum concentration and absolute concentration of NAA together with other metabolites were measured by proton magnetic resonance spectroscopy (1H-MRS) in regions with high BIDNF levels (anterior cingulate cortex [ACC], left hippocampus). Relationship between BDNF concentration and brain metabolites was studied in linear regression analysis with BDNF concentration as dependent variable and metabolite concentrations, age, and gender as predictor variables. Results: The BIDNF serum concentrations were positively associated with the concentrations of NAA (T = 2.193, p =.037) and total choline (T = 1.997, p =.055; trend) but not total creatine or glutamate in the ACC. No significant association was observed between BIDNF serum concentration and absolute metabolite concentrations in the hippocampus. Conclusions: The preliminary data might indicate that BDNF serum concentration reflects some aspects of neuronal plasticity as indicated by its association with NAA level in the cerebral cortex. The results would be in line with the notion that BIDNF plays a central role in the regulation of neuronal survival and differentiation in the human brain.