0030 BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) MET ALLELE CARRIERS SHOW IMPAIRED PERFORMANCE ON THE STROOP TASK DURING SLEEP DEPRIVATION

Abstract

Introduction: Accumulating evidence points to a genetic contribution to explain inter-individual vulnerability to sleep deprivation. A functional polymorphism in the BDNF gene, which causes a valine (Val) to methionine (Met) amino acid substitution, has been associated with cognitive impairment, particularly in populations with impaired frontal functioning. We expected that sleep deprivation, which affects frontal function, may lead to cognitive dysfunction in Met allele carriers. To examine this, we investigated the effects of sleep deprivation on response inhibition in different BDNF genotypes using the Stroop Color Naming Task. Methods: Thirty healthy, Caucasian adults aged 18–36 years, including 12 (4 women) heterozygous Met allele carriers and 18 (8 women) Val/Val homozygotes, underwent 30-hours of extended wakefulness under constant routine (CR) conditions. A computerised Stroop task was administered every 2 hours during the CR. Mean reaction time (RT) and error rate for all Stroop trials (congruent, incongruent, and neutral), and an inhibition measure (RT of incongruent trials - RT of neutral trials), were calculated for each test session and analysed using linear mixed model analysis. The difference in performance during the ‘biological night’, defined as tests occurring after dim light melatonin onset (DLMO), and during the ‘biological day’, tests occurring before DLMO, was also examined. Results: Errors and reaction times increased with time awake for all individuals. Participants with the Val/Met genotype made more errors on incongruent trials after 20 hours awake. Val/Met participants also took significantly longer to respond when inhibiting a prepotent response irrespective of time awake. Follow-up analyses, however, showed that this effect was particularly evident during the biological night. Conclusion: Our study shows that carriers of the BDNF Met allele are more vulnerable to the impact of prolonged wakefulness and the biological night on cognitive dysfunction, as measured by response inhibition on the Stroop task. Support (If Any): This study was supported by NSBRI HPF01601, HFP00003, and in part by M01-RR02635.