Abstract
This study examines whether behavioural sensitization to the dopamine agonist, quinpirole, reflects an increase in the drug’s potency and/or efficacy to induce locomotion, and how these parameters are influenced by environmental context. Three experiments were conducted in which animals received either chronic quinpirole (10×0.5 mg/kg, twice weekly) or saline injections in either the home cage environment, an alternate environment or the testing environment (activity monitors), followed by a dose-response test for the expression of sensitization in the activity monitors. Compared to the acute dose-response relationship, chronic quinpirole increased the maximum response. This increase in efficacy was significantly higher in animals treated with quinpirole in a non-home cage environment compared to those that received chronic treatment in the home cage. A leftward shift in the dose-effect function was observed only in animals with prior drug experience in the testing environment. Results indicate that locomotor sensitization to quinpirole reflects an environment-modulated increase in the drug’s efficacy, and an environment-dependent increase in drug potency. Efficacy and potency may be subject to sensitization by non-associational and associational mechanisms, respectively.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 11 April 1997 / Final version: 7 June 1997
Rights and permissions
About this article
Cite this article
Szumlinski, K., Allan, M., Talangbayan, H. et al. Locomotor sensitization to quinpirole: environment-modulated increase in efficacy and context-dependent increase in potency. Psychopharmacology 134, 193–200 (1997). https://doi.org/10.1007/s002130050442
Issue Date:
DOI: https://doi.org/10.1007/s002130050442