Chronic nicotine administration improves attention while nicotine withdrawal induces performance deficits in the 5-choice serial reaction time task in rats

Nicotine appears to enhance attention, while nicotine withdrawal leads to attentional deficits in humans that are ameliorated with nicotine administration. However, there has been much debate as to whether nicotine improves performance under baseline conditions, or only ameliorates attentional deficits. Thus, we studied the effects of acute and chronic nicotine administration and nicotine withdrawal on attentional performance in the 5-choice serial reaction time task (5-CSRTT) in Wistar and Sprague Dawley (SD) rats under baseline conditions. Wistar rats performed with higher accuracy compared to SD rats. Acute nicotine administration induced small increases in accuracy and correct responses, impulsivity and speed of responding, and decreases in omission errors. These effects were more pronounced in less accurate rats or after task modifications were implemented to disrupt the rats' performance. Chronic nicotine administration via minipumps consistently increased accuracy during days 4-6 of nicotine infusion after the effect of nicotine on impulsivity during days 1-3 dissipated. By contrast, nicotine withdrawal induced decreases in correct responses, and increases in omissions and latencies to respond, but had no effect on accuracy. These results provide evidence that chronic, but not acute, nicotine administration induced accuracy improvement under baseline conditions, while nicotine withdrawal produced some limited performance deficits. (c) 2007 Elsevier Inc. All rights reserved.