Advertisement

Psychopharmacology

, Volume 146, Issue 1, pp 42–48 | Cite as

Sensitization of apomorphine-induced stereotyped behavior in mice is context dependent

  • John J. Battisti
  • N. J. Uretsky
  • Lane J. Wallace
Original Investigation

Abstract 

Rationale: The role of the environment in the sensitization of the stereotyped behavioral effects of apomorphine is unclear, since sensitization of this drug effect has either been difficult to demonstrate or has been shown to occur with a low but not a higher dose of apomorphine. Objectives: The present study was designed to determine whether sensitization of the stereotyped behavioral effects induced by a single dose of apomorphine is dependent on environmental context. Methods: CF-1 mice were pretreated with apomorphine or vehicle under different environmental conditions and tested for stereotyped behavior after apomorphine challenge. Animals were scored positively for stereotyped behavior if they remained stationary and exhibited repetitive head and/or fore-limb movements, and data are reported as the percentage of mice rated as positive for stereotyped behavior. Results: When mice were pretreated with 40 mg/kg apomorphine and later tested in the same environment, the dose–response curve for stereotyped behavior elicited by apomorphine was shifted threefold to the left 48 h after pretreatment, and this sensitization persisted for at least 28 days after pretreatment. Mice pretreated with apomorphine did not have higher brain levels of apomorphine after administration of the test dose of apomorphine. When the pretreatment environment was different from the test environment, mice did not exhibit sensitization to apomorphine. Conclusions: These results show that pre-exposure to a single high dose of apomorphine induces a long-lasting sensitization of apomorphine-induced stereotyped behavior that is context dependent. Since apomorphine directly activates dopamine receptors, these observations suggest that a mechanism located postsynaptic to dopamine neurons may be responsible for sensitization of stereotyped behavior.

Key words Sensitization Apomorphine Stereotyped behavior Mice Environmental context 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • John J. Battisti
    • 1
  • N. J. Uretsky
    • 1
  • Lane J. Wallace
    • 1
  1. 1.Division of Pharmacology, The Ohio State University College of Pharmacy, 500 West 12th Avenue, Columbus, OH 43210, USA, e-mail: uretsky.1@osu.edu, Tel.: +1-614-292-5433, Fax: +1-614-292-9083US

Personalised recommendations