Nicotine enhances sustained attention in the rat under specific task conditions

Abstract

Although nicotine has cognitive enhancing effects in both animals and humans, most studies in humans have only shown consistent improvements in sustained attention. Moreover, many studies with smokers have been criticised, since nicotine may simply be relieving withdrawal-induced deficits. The present study investigated the effect of nicotine on sustained attention in drug-naïve rats using a five-choice serial reaction time task. Initially, the task was demonstrated to satisfy some of the criteria for the construct validity of a vigilance task: reducing signal length and either increasing or decreasing the inter-trial interval significantly (P<0.05) impaired performance. Whether nicotine (0.05-0.4 mg/kg, SC) reversed the deficits induced by a signal length of 0.25 s (weak signal) or an inter-trial-interval of either 20 s (low event rate) or 1 s (high event rate) was assessed. Nicotine (0.15 mg/kg) improved accuracy and decreased omission errors under low event rate conditions only. However, nicotine (0.05/0.15 mg/kg) improved reaction time and increased anticipatory responses under both weak signal and low event rate conditions. There was no effect of nicotine on performance under high event rate conditions. Under the low event rate condition, nicotine enhanced the ability of rats to maintain attention (i.e. accuracy) throughout a session. These findings suggest (i) that nicotine's effect on attention depends upon task characteristics; (ii) these effects on attention may reflect self-reports by smokers that nicotine aids concentration, particularly in stressful situations, and (iii) nicotinic agonists may have therapeutic benefits in patient populations suffering from attentional deficits.

Nicotine enhances acquisition of a T-maze visual discrimination: assessment of individual differences

“…fewer errors) than saline-treated rats. This finding is consistent with previous work reporting enhanced performance with nicotine treatment (Levin et al, 1990(Levin et al, , 1996% 1996bAbdulla et al, 1993;Mirza and Stolerman, 1998). However, nicotine treatment has also been shown to impair or have no effect on performance (Dunnett and Martel, 1990;Levin et al, 1997; reviewed by Levin and Simon, 1998).…”

“…Performance after nicotine (a nicotinic acetylcholine receptor agonist) treatment was examined because of the recent interest in the effects of nicotine on learning and performance. For example, nicotine treatment can improve rats' performance in a radial-arm maze (Levin et al, 1990(Levin et al, , 1996a(Levin et al, , 1996b, a Morris water maze (Abdulla et al, 1993) and a five-choice serial reaction time task (Mirza and Stolerman, 1998). In each task, variability in performance existed in nicotinetreated groups as well as in the controls.…”

The effects of serotonin and/or noradrenaline reuptake inhibitors on impulsive-like action assessed by the three-choice serial reaction time task: a simple and valid model of impulsive action using rats

“…Accuracy was not altered in the present study, though some studies reported that the administration of nicotine enhanced attentional performance in the 5-CSRTT (Mirza and Stolerman 1998;Hahn et al, 2002;Bizarro et al, 2004). This discrepancy may be due to differences in the attentional demands of the task performed between previous studies and the present study.…”

“…This discrepancy may be due to differences in the attentional demands of the task performed between previous studies and the present study. Indeed, Mirza and Stolerman (1998) found a nicotine enhancement effect on attentional performance only when the attentional demands were increased by prolonging the ITI to 20 s, while some other studies found an effect of nicotine on attentional performance under standard tasks (Hahn et al, 2002;Bizarro et al, 2004). Although the 3-CSRTT is appropriate for a brief assessment of impulsive action, its sensitivity for detecting slight changes in attentional function may be somewhat restricted.…”

Nicotinic receptor subtypes and cognitive function

“…In rat (for reviews see Brioni et al, 1997;Levin and Simon, 1998) and monkey (for review see Buccafusco et al, 1996) models of nicotine-induced cognitive improvement is more clearly seen in terms of effects on memory performance than attention, although attentional performance has been documented to be improved by nicotine in some studies (Mirza and Stolerman, 1998;McGaughy et al, 1999;Stolerman et al, 2000). These animal models are vital for the determination of the mechanisms of nicotinic-induced cognitive improvement.…”