Long-term morphine self-administration schedule in intellicages as a preclinical model of opioid abuse in mice

• Autorzy: Skupio U. , Sikora M. , Turbasa M. , Przewlocki R.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: Chronic exposure to opiates induces various alterations in brain physiology that may lead to formation of dependence, tolerance and addiction. Commonly used approaches for modeling morphine dependence involve the use of conditioned place preference, which lacks voluntary intake of the drug, and morphine self-administration, which requires isolating the animals. Here, we describe a novel model of long-term morphine self-administration in C57BL/6J mice. METHODS:We have used IntelliCage (NewBehavior, Switzerland) system to observe the animals without unnecessary experimental intervention. The animals in two separate cages were allowed access to sweetened morphine (0.5 mg/ml) or saccharin solutions for 3 executive months with saccharin concentration being gradually lowered (from 0.2% to 0.02%). We behaviorally challenged animals to test for symptoms of compulsive morphine drinking, using paradigms like saccharin reduction, progressive ratio schedule and intermittent access to rewarding substance. RESULTS: We have observed stable preference to both saccharin and morphine throughout the drinking schedule. The animals performed significantly increased number of instrumental responses to obtain access to the bottle with morphine (progressive ratio schedule) and significantly more nose pokes in attempt to obtain rewarding substance during intermittent access procedure, when compared to saccharin group. What is more, morphine dependent animals exhibited a variety of spontaneous withdrawal symptoms that lasted up to 32 hours. CONCLUSIONS: This study demonstrate that our model reliably leads to stable morphine drinking while avoiding the limitations associated with testing isolated animals. Mice drinking morphine exhibit many of the symptoms of dependence and craving compared to control animals. Therefore, this model may be well suited to screening for the effects of genetic mutations or pharmacological treatments on morphine-induced behaviors.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S91-S92

Twórcy

autor

Skupio U.

• Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Sikora M.

• Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Turbasa M.

• Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Przewlocki R.

• Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland