ERP AND NEUROTRANSMITTERS

The increasing knowledge concerning anatomical structures and cellular processes underlying event-related potentials (ERP) and methodologica l advances in ERP data analysis (e.g. dipole source analysis) begins t o bridge the gap between ERP and neurochemical aspects. Several recent reports are summarized suggesting that quite specific relationships m ay exist between certain ERP-parameters and central cholinergic, norad renergic and especially serotonergic function. Reliable indicators of the serotonin system are urgently needed because of its role in pathog enetic concepts and as target of pharmacotherapeutic interventions in psychiatric and neurologic disorders. Converging arguments from precli nical and clinical studies are presented supporting the hypothesis tha t the dependence of the auditory evoked N1/P2-response on stimulus int ensity (loudness) is regulated by the level of central serotonergic ne urotransmission. Dipole source analysis represents an important method ological advance in this context, because N1/P2-subcomponents, generat ed by different cortical structures with different serotonergic innerv ations, can be separated. A pronounced intensity dependence of the evo ked activity of primary auditory cortices is supposed to indicate a lo w central serotonergic neurotransmission and vice versa. This intensit y dependence is shown to be a parameter with clinical value because su bgroups of patients with a serotonergic dysfunction can be identified and can be treated more specifically.