Opioid-environment interaction: Contrasting effects of morphine administered in a novel versus familiar environment on acute and repeated morphine induced behavioral effects and on acute morphine ERK activation in reward associated brain areas.

We report that environmental context can have a major impact on morphine locomotor behavior and ERK effects. We manipulated environmental context in terms of an environmental novelty/ familiarity dimension and measured morphine behavioral effects in both acute and chronic morphine treatment protocols. Wistar rats (n=7 per group) were injected with morphine 10 mg/kg or vehicle (s.

Laparoscopic correction of experimentally induced diaphragmatic rupture in dogs.

Purpose: To describe the dog as a model for studying laparoscopic correction of experimental diaphragmatic ruptures.

Methods: Five male dogs were used in this study. Under laparoscopic approach, a defect of 7 cm was created on the left ventral insertion of the diaphragm.

Apomorphine locomotor sensitization can be potentiated by environmental change: evidence for a non-Pavlovian associative behavioral contrast factor in sensitization expression.

We investigated environmental contrast effects on the expression of apomorphine locomotor sensitization by using two arena formats (round and square) that elicited differential levels of spontaneous locomotion. Eight groups of rats received 3 daily injections of apomorphine (APO) (2.0mg/kg) or vehicle (VEH) to induce locomotor sensitization: four groups in the square arena (2 APO and 2 VEH) and four in the round arena (2 APO and 2 VEH).