title: Chronic stress impairs spatial memory and motivation for reward without disrupting motor ability and motivation to explore.
abstract: This study uses an operant, behavioral model to assess the daily changes in the decay rate of short-term memory, motivation, and motor ability in rats exposed to chronic restraint. Restraint decreased reward-related motivation by 50% without altering memory decay rate or motor ability. Moreover, chronic restraint impaired hippocampal-dependent spatial memory on the Y maze (4-hr delay) and produced CA3 dendritic retraction without altering hippocampal-independent maze navigation (1-min delay) or locomotion. Thus, mechanisms underlying motivation for food reward differ from those underlying Y maze exploration, and neurobiological substrates of spatial memory, such as the hippocampus, differ from those that underlie short-term memory. Chronic restraint produces functional, neuromorphological, and physiological alterations that parallel symptoms of depression in humans.
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ 85224-1107, USA.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Kleen
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Sitomer
authors.forename: Peter R
authors.initials: PR
authors.lastname: Killeen
authors.forename: Cheryl D
authors.initials: CD
authors.lastname: Conrad
mesh_terms: D000311:Adrenal Glands / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D004435:Eating / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D006624:Hippocampus / Q000473:pathology; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008569:Memory Disorders / Q000209:etiology* / Q000473:pathology; D009042:Motivation; D009043:Motor Activity / Q000502:physiology*; D009929:Organ Size / Q000502:physiology; D010424:Pentobarbital / Q000494:pharmacology; D017966:Pyramidal Cells / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D012201:Reward; D013312:Stress, Physiological / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D006993:Hypnotics and Sedatives; D010424:Pentobarbital