Effects of nicotine on motor activity, passive avoidance and plus‐maze behavior in aged NMRI and C57BL mice

Abstract

AbstractThe aim of the present study is to evaluate the effects of nicotine (0.35 and 0.175 mg/kg) on locomotor activity, passive avoidance and plus maze behavior in aged mice of two strains (C57BL and NMRI). In a first experiment, aged mice of these strains were injected with nicotine or saline and immediately afterwards were put on the actimeter. Results showed that nicotine significantly decreased locomotor activity in C57 mice. In a second experiment, nicotine was administered before training and retention sessions of a passive avoidance task. Results indicated that 0.175 mg/kg nicotine significantly increased entry latency in aged NMRI mice but had no effects on C57 mice. In the last experiment, mice were injected with nicotine and 15 min later evaluated in the plus‐maze for 5 min. It was observed that in NMRI mice no measure was significantly affected by nicotine but in C57 mice this drug significantly reduced the number of total entries, number of entries in open arms and in the central area of the maze. It is concluded that in aged mice nicotine effects depend on the baseline behaviors of the strains evaluated.