Activation of specific cortical regions by apomorphine: an [15O]H2O PET study in humans

The purpose of this study was to investigate the functional effects of apomorphine, a non-selective dopamine agonist, on regional neuronal activity using regional cerebral blood flow, measured using [15O]H2O and positron emission tomography (PET), as an index. Eight normal volunteers were scanned twice before and twice after receiving 10 micrograms/kg subcutaneous apomorphine. Apomorphine produced the expected side-effects and endocrine response. Analysis of the PET scans revealed that apomorphine increased regional cerebral blood flow (rCBF), presumably reflecting a change in neuronal activity, in the anterior cingulate, ventral motor cortex and the dorsolateral prefrontal cortex along with a decrease in rCBF in the retrosplenial cingulate region. These regions form a functional network of brain regions modulated by the dopaminergic system.