Electroencephalographic effects of intravenous nicotine--a dose-response study.

RATIONALE

It has often been demonstrated that both tobacco abstinence and nicotine have effects on the EEG power spectrum and components of the event-related potentials. In contrast, few attempts have been made to establish the dose-response relationship between nicotine and EEG parameters.

OBJECTIVES

The aim of this study was to investigate the dose-response relationship for EEG and auditory oddball P300 parameters over a wide range of intravenously infused nicotine doses.

METHOD

Fourteen regular smokers who had abstained from nicotine for at least 12 h were given intravenous infusions of 0, 3.5, 7, 14 and 28 micrograms/kg nicotine over 10 min in a single-blind randomised cross-over design. Parallel recordings of spontaneous EEG, auditory P300 and heart rate, as well as venous blood sampling were made before, during and after nicotine administration.

RESULTS

Linear dose-related decreases of delta and theta power were found, along with increases in alpha2 power and alpha peak frequency. Alpha1, beta and P300 parameters were unaffected.

CONCLUSION

Our results are consistent with nicotine-dependent changes in EEG measures indicative of arousal.