Nicotine sensitization (Part 2): Time spent in the centre of an open field sensitizes to repeated nicotine into the drug-free state in female rats.

Repeated nicotine sensitized the time spent in the centre of an open field with the long-lasting sensitization of this measure of anxiety-like behaviour evident in a drug-free state, in contrast to locomotor sensitization which does not persist in the drug-free state. The results suggest independence of the mechanisms of sensitization that underlie locomotor and anxiolytic effects.