Affiliation: School of Medicine, UNC Neuroscience Center, Neuroscience Curriculum
Dopamine projections that extend from the ventral tegmental area to the striatum have been implicated in the biological basis for behaviors associated with reward, addiction, and neurodegenerative disorders, such as Parkinson's disease. Many techniques have been employed to monitor these neurochemical and neurophysiological changes. In this study we utilized fast-scan cyclic voltammetry to monitor transient pH and oxygen changes in the striatum of primates. Dopamine release was observed in a small number of locations, but this signal was masked by the overarching pH changes. Oxygen and pH are coupled in the brain through a complex system of blood flow and metabolism as a result of transient neural activity. Indeed, this balance is at the heart of imaging studies such as functional magnetic resonance imaging (fMRI). We observed increases in pH to the cue onset and increases in oxygen to predicted reward delivery, respectively. Additionally, acidic pH changes were observed following probability predicted reward delivery and to the cue onset in a small percentage of cases. These findings show that pH, oxygen, and dopamine can be measured in primate striatum and have implications linking blood flow and metabolism to neural activity.