Unidirectional opioid-cannabinoid cross-tolerance in the modulation of social play behavior in rats
Rationale: The endocannabinoid and the endogenous opioid systems interact in the modulation of social play behavior, a highly rewarding social activity abundantly expressed in young mammals. Prolonged exposure to opioid or cannabinoid receptor agonists induces cross-tolerance or cross-sensitization to their acute behavioral effects.