Differential effects of propranolol on conditioned hyperactivity and locomotor sensitization induced by morphine in rats.
According to memory reconsolidation theory, when long-term memory is reactivated by relevant clues, the memory traces become labile, which can be altered by pharmacological manipulations. Accumulating evidence reveals that memory related to drug abuse can be erased by disrupting reconsolidation process. We used an animal model that could simultaneously measure conditioned hyperactivity and locomotor sensitization induced by morphine. β-Adrenoceptor antagonist propranolol or saline were administered following conditioned stimuli (CS) or a small dose of morphine reactivation. The results showed that the conditioned hyperactivity could be disrupted by propranolol treatment following CS reactivation. However, the expression of locomotor sensitization could not be disrupted by propranolol administration following CS or morphine reactivation. Furthermore, morphine injection and propranolol intervention enhanced the locomotor sensitization effect. These data suggest that blocking the reconsolidation process can disrupt the conditioned hyperactivity induced by environmental cues associated with morphine treatment, but not morphine-induced locomotor sensitization.
1] Beijing Key Laboratory of Learning and Cognition, Department of Psychology, Capital Normal University, Beijing 100048, China [2] College of Education Science and Teacher Development, Henan Normal University, Xinxiang 453007, China.
Shuguang
S
Wei
Beijing Key Laboratory of Learning and Cognition, Department of Psychology, Capital Normal University, Beijing 100048, China.
Xinwang
X
Li
D018674:Adrenergic Antagonists / Q000378:metabolism; D000818:Animals; D003213:Conditioning, Psychological / Q000187:drug effects; D006801:Humans; D006948:Hyperkinesis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D057567:Memory, Long-Term / Q000187:drug effects; D009020:Morphine / Q000008:administration & dosage*; D009043:Motor Activity / Q000187:drug effects*; D011433:Propranolol / Q000008:administration & dosage*; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism
D018674:Adrenergic Antagonists; D011941:Receptors, Adrenergic; D009020:Morphine; D011433:Propranolol