Psychopharmacology

, Volume 215, Issue 4, pp 609–620

Behavioral sensitization to cocaine in rats: evidence for temporal differences in dopamine D3 and D2 receptor sensitivity

  • Gregory T. Collins
  • Yen Nhu-Thi Truong
  • Beth Levant
  • Jianyong Chen
  • Shaomeng Wang
  • James H. Woods
Original Investigation

DOI: 10.1007/s00213-010-2154-7

Cite this article as:
Collins, G.T., Truong, Y.NT., Levant, B. et al. Psychopharmacology (2011) 215: 609. doi:10.1007/s00213-010-2154-7
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Abstract

Rationale

Cocaine-induced changes in D2 receptors have been implicated in the expression of sensitized behavioral responses and addiction-like behaviors; however, the influence of D3 receptors is less clear.

Objectives

To characterize the effects of repeated cocaine administration on the sensitivity of rats to D2- and D3-mediated behaviors, as well as the binding properties of ventral striatal D2-like and D3 receptors.

Methods

Pramipexole was used to assess the sensitivity of rats to D3/D2 agonist-induced yawning, hypothermia, and locomotor activity, 24 h, 72 h, 10, 21, and 42 days after repeated cocaine or saline administration. The locomotor effects of cocaine (42 day) and the binding properties of ventral striatal D2-like and D3 receptors (24 h and 42 days) were also evaluated.

Results

Cocaine-treated rats displayed an enhanced locomotor response to cocaine, as well as a progressive and persistent leftward/upward shift of the ascending limb (72 h–42 day) and leftward shift of the descending limb (42 days) of the pramipexole-induced yawning dose–response curve. Cocaine treatment also decreased Bmax and Kd for D2-like receptors and increased D3 receptor binding at 42 days. Cocaine treatment did not change pramipexole-induced hypothermia or locomotor activity or yawning induced by cholinergic or serotonergic agonists.

Conclusions

These studies suggest that temporal differences exist in the development of cocaine-induced sensitization of D3 and D2 receptors, with enhancements of D3-mediated behavioral effects observed within 72 h and enhancements of D2-mediated behavioral effects apparent 42 days after cocaine. These findings highlight the need to consider changes in D3 receptor function when thinking about the behavioral plasticity that occurs during abstinence from cocaine use.

Keywords

Cocaine Sensitization Dopamine D2 receptor Dopamine D3 receptor Yawning Pramipexole 

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Gregory T. Collins
    • 1
  • Yen Nhu-Thi Truong
    • 1
  • Beth Levant
    • 2
  • Jianyong Chen
    • 3
  • Shaomeng Wang
    • 1
    • 3
  • James H. Woods
    • 1
  1. 1.Department of PharmacologyUniversity of Michigan Medical SchoolAnn ArborUSA
  2. 2.Department of Pharmacology, Toxicology, and TherapeuticsUniversity of Kansas Medical CenterKansas CityUSA
  3. 3.Departments of Internal Medicine and Medicinal ChemistryUniversity of Michigan Medical SchoolAnn ArborUSA

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