Urinary Brain-Derived Neurotrophic Factor as a Biomarker of Executive Functioning

Abstract

Background/Aims: Neurotrophins such as brain-derived neurotrophic factor (BDNF) are vital for neuronal survival and adaptive plasticity. With high BDNF gene expression in the prefrontal cortex, BDNF is a potential regulatory factor for building and maintaining cognitive reserves. Recent studies suggest that individual differences in executive functioning, a broad cognitive domain reliant upon frontal lobe structure and function, are governed in part by variance in BDNF polymorphisms. However, as neurogenetic data are not necessarily indicative of in vivo neurochemistry, this study examines the relationship between executive functioning and the neurotransmitter by measuring peripheral BDNF levels. Methods: Fifty-two healthy young adults completed a battery of standardized executive function tests. BDNF levels, adjusted for creatinine, were quantified with enzyme-linked immunosorbent assay of urine samples taken at the time of testing. Results: BDNF concentration was positively associated with cognitive flexibility but had no relationship with working memory, abstract reasoning/planning, self-monitoring/response inhibition, or fluency. Conclusions: These results individuate cognitive flexibility as the specific facet of executive functioning associated with in vivo BDNF levels. This study also validates urinary BDNF as a peripheral biomarker of cognition in healthy adults.