Diminished Compensatory Energy Production Following Hypoxic Stress in the Prefrontal and Anterior Cingulate Cortex...

The purpose of this study was to explore the capacity for energy production under conditions of increased energy demand in schizophrenia (SCZ) subjects compared to healthy controls.

Twelve healthy controls (33.00±6.07 years) and 12 subjects diagnosed with SCZ or schizoaffective disorder (36.00±8.33 years) matched for age and sex, were recruited for this study. Hypoxic stress was induced during MR scans to elevate the energy demand on the subjects' bioenergetic systems. Participants breathed air with a lower oxygen concentration (FiO2=13%), maintaining their SpO2 levels (86%) during the initial phase of the scan. 31Phosphorus MR spectroscopy was employed to examine metabolite levels, including phosphocreatine (PCr), β-adenosine triphosphate (ATP), and inorganic phosphate (Pi), as well as the ratios of PCr/Pi and PCr/β-ATP, in regions such as the prefrontal cortex (PFC), anterior cingulate cortex (ACC), and posterior cortex (POC), as well as across the entire brain, during both hypoxia and hyperoxia scans.

Subjects with SCZ had significantly lower levels of Pi across the brain and particularly, in the PFC, POC, and ACC during the hypoxia scan. Moreover, levels of PCr/Pi, indicative of mitochondrial energy production, were found to be higher in the same brain regions in the SCZ group. No significant differences were found in hyperoxia scan phase.

These findings suggest a deficit in the bioenergetic systems of individuals with SCZ under conditions of heightened energy demand. Further studies are warranted.