The human brain exhibits asymmetric hemispheric activity at night; this plays acrucial role in cognitive impairment from sleep deprivation. Although there havebeen many investigations on this topic, there are no studies on hemisphericdifferences in the consumption of high-energy phosphates (HEP). We presenthere a new data analysis of our previously published study in which subjects weremeasured for changes in high-energy phosphate (HEP), tCr/tNAA, and Glu/TNAAduring subacute sleep deprivation (21 h) and cognitive tests. In our new analysis,we investigated differences and asymmetries in the metabolic consumption ofboth hemispheres. Comprehensive per-individual voxel-wise interhemisphericcomparisons at all time points and conditions showed a greater decrease frombaseline of ATP in the right than in the left hemisphere. Partial volume correctionyielded an apparent higher decline of PCr/Pi in gray versus white matter. We alsoinvestigated whether creatine supplementation, which has been shown to preventcognitive impairment during sleep deprivation, affected this hemispheric asymmetry.In a second session, the subjects took a high single dose of creatine monohydratesuspension (0.35 g/kg) after baseline measurements. Creatine balanced the sleepdeprivation-induced asymmetry to a higher degree in the left hemisphere, whichwas due to an increase in PCr/Pi and decrease in ATP. Our results confirm—viathe observed decrease in ATP level—a night-active right hemisphere. Creatineadministration balanced this asymmetry.
Gordjinejad et al. (Wed,) studied this question.