title: Chronic stress may facilitate the recruitment of habit- and addiction-related neurocircuitries through neuronal restructuring of the striatum.
abstract: Chronic stress is an established risk factor in the development of addiction. Addiction is characterized by a progressive transition from casual drug use to habitual and compulsive drug use. The ability of chronic stress to facilitate the transition to addiction may be mediated by increased engagement of the neurocircuitries underlying habitual behavior and addiction. In the present study, striatal morphology was evaluated after 2 weeks of chronic variable stress in male Sprague-Dawley rats. Dendritic complexity of medium spiny neurons was visualized and quantified with Golgi staining in the dorsolateral and dorsomedial striatum, as well as in the nucleus accumbens core and shell. In separate cohorts, the effects of chronic stress on habitual behavior and the acute locomotor response to methamphetamine were also assessed. Chronic stress resulted in increased dendritic complexity in the dorsolateral striatum and nucleus accumbens core, regions implicated in habitual behavior and addiction, while decreased complexity was found in the nucleus accumbens shell, a region critical for the initial rewarding effects of drugs of abuse. Chronic stress did not affect dendritic complexity in the dorsomedial striatum. A parallel shift toward habitual learning strategies following chronic stress was also identified. There was an initial reduction in acute locomotor response to methamphetamine, but no lasting effect as a result of chronic stress exposure. These findings suggest that chronic stress may facilitate the recruitment of habit- and addiction-related neurocircuitries through neuronal restructuring in the striatum.
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA. Electronic address: taylor@hendrix.edu.
authors.forename: S B
authors.initials: SB
authors.lastname: Taylor
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Anglin
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Paode
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Riggert
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA; Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Olive
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA; Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, USA. Electronic address: conradc@asu.edu.
authors.forename: C D
authors.initials: CD
authors.lastname: Conrad
mesh_terms: D019969:Amphetamine-Related Disorders / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D016739:Behavior, Addictive / Q000473:pathology / Q000503:physiopathology; D000697:Central Nervous System Stimulants / Q000633:toxicity; D002908:Chronic Disease; D003342:Corpus Striatum / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D003712:Dendrites / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D004195:Disease Models, Animal; D006184:Habits; D007858:Learning / Q000187:drug effects / Q000502:physiology; D008297:Male; D008694:Methamphetamine / Q000633:toxicity; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000473:pathology / Q000503:physiopathology*
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine
keywords: Golgi; chronic variable stress; habit; methamphetamine; nucleus accumbens; striatum