Feeding or exposure to food odors increases extracellular DOPAC levels (as measured by in vivo voltammetry) in the prefrontal cortex of food-deprived rats.

The effects of feeding or of exposure to food odors (without opportunity to feed) on dopamine metabolism in the prefrontal cortex have been investigated in rats food deprived for 24 h. Dopamine metabolism was assessed by measuring extracellular DOPAC levels by in vivo voltammetry with carbon fiber electrodes. Feeding in fasted rats was accompanied by an increase in extracellular cortical DOPAC levels which gradually returned to basal levels within 90 min after the onset of meal. A similar, though slightly less pronounced, increase in cortical dopamine metabolism was found in fasted rats exposed to food odors but not allowed to feed. These results indicate that feeding or the olfactory stimulation associated with food presentation causes an increase in mesocortical dopaminergic neuron activity.