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Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats.

Publication ,  Journal Article
Rezvani, AH; Bushnell, PJ; Levin, ED
Published in: Psychopharmacology (Berl)
December 2002

RATIONALE: During the past decade, central nicotinic systems have been shown in both experimental animals and humans to play an important role in cognitive function. However, the way in which specific aspects of cognitive function are affected by nicotinic systems has remained unclear. In humans, the most pronounced action of nicotine is to improve attention, but in rats, memory improvement is more easily seen. This may be due to differences in methods for assessing attention in rats and humans or to species differences in the roles of nicotinic systems in cognitive function. In the current study, we explored the effects of nicotine and mecamylamine using an operant visual signal detection task designed to model sustained attention processes common to rats and humans. METHODS: Adult female rats ( n=35) were trained to perform the signal detection task to a stable baseline of about 75% accuracy. The rats were then assigned to two subgroups of high and low accuracy based on overall accuracy (hits and correct rejections) at the end of training. All rats were then injected (SC, 10 min before testing) with saline or different doses of nicotine (0.0125, 0.025, 0.05, 0.1, 0.2 and 0.4 mg/kg) or the nicotinic antagonist mecamylamine (1, 2 and 4 mg/kg). RESULTS: A low dose range of nicotine (0.0125, 0.025, and 0.05 mg/kg) caused a dose-related increase in percent correct rejection. This dose range did not affect correct detections of the signal (percent hit). Higher doses of nicotine (0.1, 0.2 and 0.4 mg/kg) did not affect percent correct rejection, but did have a time-dependent effect on percent hit. Early in the session, the higher doses of nicotine reduced percent hit, whereas during the later part of the session higher doses of nicotine increased percent hit. Effects of nicotine did not differ between the high- and low-accuracy rats. Mecamylamine decreased choice accuracy, reducing both percent hit and percent correct rejection. Mecamylamine reduced percent hit in the low-accuracy rats at a lower drug dose than in the high-accuracy rats. CONCLUSIONS: These results support the involvement of nicotinic systems in attention in rats, as has been shown in humans. This rat model of sustained attention may provide a good approach to studying neural mechanisms underlying the effects of nicotinic cholinergic receptors on attention and a means to evaluate the potential of novel nicotinic agonists to counteract attentional dysfunction.

Duke Scholars

Published In

Psychopharmacology (Berl)

DOI

ISSN

0033-3158

Publication Date

December 2002

Volume

164

Issue

4

Start / End Page

369 / 375

Location

Germany

Related Subject Headings

  • Signal Detection, Psychological
  • Reaction Time
  • Rats, Sprague-Dawley
  • Rats
  • Psychiatry
  • Nicotinic Antagonists
  • Nicotine
  • Mecamylamine
  • Female
  • Dose-Response Relationship, Drug
 

Citation

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Rezvani, A. H., Bushnell, P. J., & Levin, E. D. (2002). Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats. Psychopharmacology (Berl), 164(4), 369–375. https://doi.org/10.1007/s00213-002-1221-0
Rezvani, Amir H., Philip J. Bushnell, and Edward D. Levin. “Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats.Psychopharmacology (Berl) 164, no. 4 (December 2002): 369–75. https://doi.org/10.1007/s00213-002-1221-0.
Rezvani AH, Bushnell PJ, Levin ED. Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats. Psychopharmacology (Berl). 2002 Dec;164(4):369–75.
Rezvani, Amir H., et al. “Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats.Psychopharmacology (Berl), vol. 164, no. 4, Dec. 2002, pp. 369–75. Pubmed, doi:10.1007/s00213-002-1221-0.
Rezvani AH, Bushnell PJ, Levin ED. Effects of nicotine and mecamylamine on choice accuracy in an operant visual signal detection task in female rats. Psychopharmacology (Berl). 2002 Dec;164(4):369–375.
Journal cover image

Published In

Psychopharmacology (Berl)

DOI

ISSN

0033-3158

Publication Date

December 2002

Volume

164

Issue

4

Start / End Page

369 / 375

Location

Germany

Related Subject Headings

  • Signal Detection, Psychological
  • Reaction Time
  • Rats, Sprague-Dawley
  • Rats
  • Psychiatry
  • Nicotinic Antagonists
  • Nicotine
  • Mecamylamine
  • Female
  • Dose-Response Relationship, Drug