Stimulus- and event-related evoked potentials: from neuroscience to clinical neuropharmacology.

Synaptic neural (and neural system) functions are peculiarly sensitive to neuroactive compounds. Pharmacological interference/modulation is readily reflected by modifications in the organization of central nervous system (CNS), electrophysiologic signals occurring spontaneously in response to sensory stimulation (stimulus-related or evoked responses) or elicited in conjunction with sensory, motor or cognitive evems (event-related potentials). Evoked responses reflect the basic physiology of sensory processes, while event-related potentials combine the time/space resolution of electrophysiologic signals with the specificity of eliciting neuropsychological conditions. The rationale for investigating drug effects on evoked and eventrelated potentials is manifold. Both are related to sensory and operant behavior and under suitable experimental conditions allow interpretation of drug-related changes in terms of CNS excitability. Some continuity between observations in man and in vivo or in vitro animal data is often possible. Proper handling of the stimulus physical properties or experimental/situational links may allow the responses to be related to sensory input or to neuropsychological manipulation of selectively activated CNS functions or functional subsystems and therefore to control spontaneous variability. This review summarizes today's knowledge of the application of electrophysiology to human neuropharmacology, with the reference to basic pharmacology and experimental evidence.