Skip to main content
Log in

Systemic pretreatment with MK-801 (dizocilpine) increases breaking points for self-administration of cocaine on a progressive-ratio schedule in rats

  • ORIGINAL INVESTIGATION
  • Published:
Psychopharmacology Aims and scope Submit manuscript

Abstract

 The effects of the noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801, on cocaine self-administration were investigated. Forty-six male Wistar rats were trained to intravenously self-administer four unit doses of cocaine (0.19, 0.38, 0.75 and 1.5 mg/kg per injection) on a progressive-ratio schedule of reinforcement. The effects of increasing doses of MK-801 (0.05, 0.1, 0.15 and 0.2 mg/kg, IP, 30 min before test sessions) on breaking point (BP) for cocaine self-administration were investigated. The results showed that pretreatment with MK-801 produced effects on cocaine BPs that fit on an inverted-U function. That is, the 0.05 and 0.1 mg/kg doses of MK-801 produced no effect or a small enhancement of BPs across all doses of cocaine, respectively. The 0.15 mg/kg dose of MK-801 produced a significant treatment effect characterized by increased BPs, relative to baseline BPs, across all doses of cocaine. The 0.2 mg/kg dose of MK-801 produced a nonsignificant decrease in BPs across most doses of cocaine. The dose-dependent effects on cocaine BPs after pretreatment with MK-801 suggest that MK-801 can potentiate, and at higher doses attenuate, the rewarding effects of self-administered cocaine.

This is a preview of subscription content, log in via an institution to check access.

Access this article

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

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Additional information

Received: 3 January 1996 / Final version: 12 June 1996

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ranaldi, R., French, E. & Roberts, D. Systemic pretreatment with MK-801 (dizocilpine) increases breaking points for self-administration of cocaine on a progressive-ratio schedule in rats. Psychopharmacology 128, 83–88 (1996). https://doi.org/10.1007/s002130050113

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/s002130050113

Navigation