Nicotine self-administration in rats: estrous cycle effects, sex differences and nicotinic receptor binding (original) (raw)

Abstract.

Rationale: Research on smoking behavior and responsiveness to nicotine suggests that nicotine's effects may depend on the sex of the organism. Objective: The present study addressed four questions: 1) Will female rats self-administer nicotine? 2) Does self-administration by females vary as a function of estrous cycle? 3) Does self-administration by females differ from that of males? 4) Does self-administration of nicotine result in up-regulation of nicotinic receptor binding and are these changes similar in males and females? Methods: Male and female Sprague-Dawley rats were allowed to self-administer nicotine at one of four doses (0.02–0.09 mg/kg, free base) on both fixed and progressive ratio schedules of reinforcement. Results: Females acquired nicotine self-administration across the entire range of doses. Acquisition of self-administration at the lowest dose was faster in females than males. However, few sex differences were found in the number of active responses, number of infusions, or total intake of nicotine during stable fixed ratio self-administration. In contrast, females reached higher break points on a progressive ratio. For both schedules, females had shorter latencies to earn their first infusion of each session and demonstrated higher rates of both inactive and timeout responding. There was no effect of estrous cycle on self-administration during either fixed or progressive ratio sessions. Self-administered nicotine resulted in average arterial plasma nicotine levels between 53 and 193 ng/ml and left hemi_-_brain levels between 174 and 655 ng/g, depending on dose. Nicotine self-administration produced similar up-regulation of nicotinic receptor binding sites in males and females, as reflected by increased right hemi-brain binding of [3H]-epibatidine, when compared to the brains of untreated control rats. Conclusions: These results suggest that while males and females may regulate their intake of nicotine similarly under limited access conditions, the motivation to obtain nicotine is higher in females.

Access this article

Log in via an institution

Subscribe and save

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Author information

Authors and Affiliations

  1. Behavioral Pharmacology Research Unit, Department of Psychiatry, Johns Hopkins Bayview Medical Center, 5510 Nathan Shock Drive, Baltimore, MD 21224-6823, USA, , , , ,
    E.C. Donny
  2. Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA, , , , ,
    A.R. Caggiula, M.A. Gharib, V. Maldovan, S. Booth, M.M. Mielke, A. Hoffman & S. McCallum
  3. Department of Pharmacology, University of Louisville School of Medicine, Louisville, Kentucky, USA, , , , ,
    P.P. Rowell

Authors

  1. E.C. Donny
  2. A.R. Caggiula
  3. P.P. Rowell
  4. M.A. Gharib
  5. V. Maldovan
  6. S. Booth
  7. M.M. Mielke
  8. A. Hoffman
  9. S. McCallum

Additional information

Electronic Publication

Rights and permissions

About this article

Cite this article

Donny, E., Caggiula, A., Rowell, P. et al. Nicotine self-administration in rats: estrous cycle effects, sex differences and nicotinic receptor binding.Psychopharmacology 151, 392–405 (2000). https://doi.org/10.1007/s002130000497

Download citation