Neurons are almost exclusively cultured in media containing glucose at much higher concentration than found in the brain. To test whether “standard” hyperglycaemic culture conditions affect neuronal respiration compared to near- euglycemic conditions, we grew neuronal cultures with minimal glial contamination from hippocampus and cortex of neonatal C57bl6 mice in standard commercially available media (25 mM Glucose) and in identical media with 5 mM glucose. Neurons grew well in both glucose concentrations until at least 14 days in vitro, with similar morphology and synaptogenesis. Neurons grown in high glucose were more dependent on glycolysis as their primary source of ATP, measured using ATP luminescence and cellular respirometry assays. In contrast, neurons grown in 5 mM glucose showed a more balanced dependence on glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) and greater reserve mitochondrial respiration capacity, relative to standard media. Changes in gene and protein expression levels corroborate these changes in function. Our results suggest that neurons cultured in high glucose media preferentially use glycolysis, opposite to what is known for neurons in vivo as the primary pathway for ATP maintenance. We suggest using neuronal culture systems in 5 mM glucose to better represent physiologically relevant neuronal respiration.