Extinction of appetitive learning is disrupted by cycloheximide and propranolol in the sand maze in rats

• Published in: Neurobiology of learning and memory Vol. 95; no. 4; pp. 484 - 490
• Main Authors: Cohen, Joshua, Gotthard, Gretchen Hanson
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.05.2011; Elsevier; Elsevier BV
• Subjects: Adrenergic beta-Antagonists - pharmacology; Analysis of Variance; Animal cognition; Animal memory; Animals; Appetitive; Appetitive Behavior - drug effects; Behavioral psychophysiology; Beta blockers; Biological and medical sciences; Cereals; Cycloheximide; Cycloheximide - pharmacology; Exploratory Behavior - drug effects; Extinction; Extinction, Psychological - drug effects; Fundamental and applied biological sciences. Psychology; Inhibitor drugs; Learning; Male; Maze Learning - drug effects; Memory; Memory consolidation; Nervous system; Neurobiology; Non-spatial learning; Propranolol; Propranolol - pharmacology; Protein biosynthesis; Protein Synthesis Inhibitors - pharmacology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Long-Evans; Reaction Time - drug effects; Reinforcement; Rodents; Sand; Spatial Behavior - drug effects; Spatial discrimination learning; Spatial learning; spatial memory; Sweet taste; Time Factors; Transfer learning; β-Adrenergic antagonist; Memory consolidation; Non-spatial learning; Cycloheximide; Appetitive; Extinction; Propranolol; β-Adrenergic antagonist; Spatial learning; Rat; Memory; Rodentia; Space perception; Antiarrhythmic agent; β-Adrenergic receptor; Vertebrata; Mammalia; Acquisition process; Consolidation; Animal; Antagonist; Perceptive learning; Beta blocking agent
• ISSN: 1074-7427; 1095-9564
• DOI: 10.1016/j.nlm.2011.02.011

► Cycloheximide and propranolol block extinction memory in a non-spatial version of the sand maze. ► Effects of cycloheximide and propranolol transfer to learning spatial version of the sand maze. ► Protein synthesis and beta-adrenergic activity necessary for extinction in appetitive task. The present study investigated whether memory for extinction in an appetitive task (the sand maze) could be attenuated by administration of cycloheximide (protein synthesis inhibitor) or propranolol (β-adrenergic receptor antagonist). Ninety-day-old male Long-Evans rats were trained to retrieve a sweet cereal reinforcer from an open container in the sand maze. One day following this non-spatial training, rats received three extinction trials in which they were placed in the maze with the reinforcer present, but unattainable. Thirty minutes prior to the first extinction trial, rats received an intraperitoneal injection of cycloheximide (1mg/kg), propranolol (25mg/kg), or vehicle (1mg/kg distilled water). Twenty-four hours later, rats were tested in the sand maze with the reinforcer again available. Results from the test trial showed that both cycloheximide and propranolol groups found the reinforcer more quickly than controls. Two weeks later, rats were trained on a spatial version of the sand maze in which they had to search for a buried reinforcer using extramaze cues. Cycloheximide and propranolol groups learned this task significantly faster than the control group, demonstrating the long-lasting effect of cycloheximide and propranolol on the blocking of memory for extinction.