A new place conditioning paradigm to study tolerance to opiates in mice.
Tolerance to the rewarding properties of morphine was investigated in mice using a new conditioned place preference (CPP) procedure. Four pairings of morphine with specific environmental cues induced a significant CPP for the drug-paired cues. Further opiate conditioning trials in the presence of the same environmental cues revealed no change in the drug-induced CPP on repeated test sessions. Subsequent exposure of the same animals to conditioning trials by pairing morphine with a set of novel environmental cues showed that the opiate was still able to produce a CPP in mice treated with a total of 16 morphine injections. The present CPP paradigm may prove useful to investigate tolerance to the rewarding properties of drugs of abuse.
Contarino
A
A
Dipartimento di Farmacologia, Padova, Italy.
Drago
F
F
Zanotti
A
A
Natolino
F
F
Berti
T
T
Giusti
P
P
D000818:Animals; D002755:Choice Behavior / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology*; D003463:Cues; D004361:Drug Tolerance; D004777:Environment; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000494:pharmacology*; D012201:Reward
D009020:Morphine