DRD2 C957T genotype modulates the time-on-task effect during total sleep deprivation

Area of Science:

• Neuroscience
• Genetics
• Sleep Research

Background:

• Total sleep deprivation (TSD) and prolonged time-on-task (TOT) significantly impair cognitive functions and performance.
• Individual responses to TSD and TOT vary considerably, with a portion of this variability attributable to genetic factors.

Purpose of the Study:

• To investigate the genetic underpinnings of inter-individual differences in cognitive performance during TSD and TOT.
• To determine if the dopamine receptor D2 (DRD2) C957T polymorphism influences performance decrements on a psychomotor vigilance test (PVT) under sustained sleep deprivation.

Main Methods:

• Participants underwent 38 hours of total sleep deprivation.
• Cognitive performance was assessed using the psychomotor vigilance test (PVT).
• Genotyping for the dopamine receptor D2 C957T polymorphism was performed.

Main Results:

• The dopamine receptor D2 C957T genetic polymorphism significantly predicted the magnitude of the time-on-task effect on PVT performance during 38 hours of TSD.
• Individuals with specific DRD2 genotypes exhibited differential susceptibility to performance decline with increasing time-on-task under sleep deprivation.

Conclusions:

• Dopamine availability, modulated by the DRD2 C957T polymorphism in brain regions like the striatum, plays a crucial role in the time-on-task effect during sleep loss.
• These findings suggest that dopaminergic pathways are involved in the mechanisms underlying sustained attention deficits induced by sleep deprivation.