Electroencephalographic characterization of brain dopaminergic stimulation by apomorphine in healthy volunteers

Apomorphine, a dopamine receptor agonist (given in a dose of 0.75 mg s.c.), was administered to 8 healthy volunteers; electroencephalograph (EEG) and event-related potential (ERP) mapping were performed before dosing and 0.5, 1.5 and 2.5 h after dosing. Apomorphine caused an overall increase in beta activity at time 0.5 h in both absolute and relative energy; P300 and CNV ERPs were not significantly altered, although a tendency towards increased P300 latency was seen. The results confirm that the EEG mapping technique is sufficiently sensitive to monitor dopaminergic neurochemical stimulation by means of apomorphine. This could lead to a new, non-invasive and repeatable method for monitoring central neuronal systems which is more convenient to apply repeatedly than for example positron emission tomography techniques. Furthermore, electrophysiological techniques undoubtedly constitute an alternative to classical neuroendocrinological methods, allowing a more direct assessment of central nervous system neurotransmission. Finally, these EEG approaches could lead to better characterization of drugs acting on dopaminergic pathways, such as antipsychotics.