Is learning ability and spatial memory in rats influenced by single dose of nicotine?

A lot of studies have been concentrated on an effect of a short or a long-term administration of nicotine in humans or in animals. The negative effects on the human organism have been known for a long time, but these health problems are known especially from observing smokers. The number of tasks in human and in animals with accent on positive effect of nicotine has increased especially with regard to improvement of cognitive functions. The aim of this study was to investigate, how much a single dose of nicotine can influence the learning ability in rats. Male Wistar albino rats, 25-day-old, were studied. Two groups of animals received an intraperitoneal (i.p.) injection of nicotine in two different doses (0.75 mg/kg and 1.00 mg/kg b.w.). The third group received a single i.p. injection of saline in the equal volume (the control group). After the drug application the escape latency and the path length were measured and assessed in two periods of sessions in the Morris water maze. In our study no explicit changes of learning ability after a single nicotine injection was confirmed. Only at the third day of the task the trajectory was shorter (p<0.05) but this result appears too isolated. So we cannot exclude that such improvement was caused by other factors than by the nicotine administration.