Morphine-induced conditioned place preference in preweanling and adult rats

C. K. Randall, P. J. Kraemer, M. T. Bardo

Research output: Contribution to journalArticlepeer-review

43 Scopus citations


The ability of morphine to support a conditioned place preference (CPP) in preweanling (18-22-day-old) and adult (70-90-day-old) rats was assessed. Prior to a 15-min compartment preference test, subjects received a saline-paired, 30-min exposure to a distinct compartment 2 h prior to receiving an injection of 1 or 5 mg/kg of morphine or saline, paired with a 30-min exposure to an alternate compartment for 4 consecutive days. Although overall activity levels differed substantially across age, preweanling and adult rats displayed similar patterns of activity during conditioning. Moreover, only adults exhibited a significant sex difference; females were more active than were males following an injection of 5 mg/kg of morphine. Both doses of morphine supported a comparable CPP in preweanlings and adults, and both ages exhibited relatively low activity levels while in the morphine-paired compartment. These similarities across age suggest that the CPP procedure may prove to be useful in elucidating the ontogeny of learning, memory, and stimulus selection in rats.

Original languageEnglish
Pages (from-to)217-222
Number of pages6
JournalPharmacology Biochemistry and Behavior
Issue number1
StatePublished - May 1998


  • CPP
  • Conditioned place preference
  • Morphine
  • Ontogeny
  • Rattus norvegicus

ASJC Scopus subject areas

  • Biochemistry
  • Toxicology
  • Pharmacology
  • Clinical Biochemistry
  • Biological Psychiatry
  • Behavioral Neuroscience


Dive into the research topics of 'Morphine-induced conditioned place preference in preweanling and adult rats'. Together they form a unique fingerprint.

Cite this