We sought to determine the cerebral metabolic fate of glucose during sound stimulation in near-term fetal sheep. Blood oxygen content was significantly decreased by 6-7% during sound stimulation. The cerebral glucose:oxygen quotient increased from 0.88 +/- 0.08 to 1.13 +/- 0.12 (mean +/- S.E.M., P < 0.01). This is consistent with the phenomenon of stimulated glycolysis which has been shown to increase brain lactate concentration in other models.