Prolonged corticosterone exposure induces dendritic spine remodeling and attrition in the rat medial prefrontal cortex.

Autor: Anderson RM; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242., Glanz RM; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242., Johnson SB; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242., Miller MM; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242., Romig-Martin SA; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242., Radley JJ; Department of Psychological and Brain Sciences and Program in Neuroscience, University of Iowa, Iowa City, Iowa, 52242. jason-radley@uiowa.edu.
Jazyk: angličtina
Zdroj: The Journal of comparative neurology [J Comp Neurol] 2016 Dec 15; Vol. 524 (18), pp. 3729-3746. Date of Electronic Publication: 2016 May 17.
DOI: 10.1002/cne.24027
Abstrakt: The stress-responsive hypothalamo-pituitary-adrenal (HPA) axis plays a central role in promoting adaptations acutely, whereas adverse effects on physiology and behavior following chronic challenges may result from overactivity of this system. Elevations in glucocorticoids, the end-products of HPA activation, play roles in adaptive and maladaptive processes by targeting cognate receptors throughout neurons in limbic cortical networks to alter synaptic functioning. Because previous work has shown that chronic stress leads to functionally relevant regressive alterations in dendritic spine shape and number in pyramidal neurons in the medial prefrontal cortex (mPFC), this study examines the capacity of sustained increases in circulating corticosterone (B) alone to alter dendritic spine morphology and density in this region. Subcutaneous B pellets were implanted in rats to provide continuous exposure to levels approximating the circadian mean or peak of the steroid for 1, 2, or 3 weeks. Pyramidal neurons in the prelimbic area of the mPFC were selected for intracellular fluorescent dye filling, followed by high-resolution three-dimensional imaging and analysis of dendritic arborization and spine morphometry. Two or more weeks of B exposure decreased dendritic spine volume in the mPFC, whereas higher dose exposure of the steroid resulted in apical dendritic retraction and spine loss in the same cell population, with thin spine subtypes showing the greatest degree of attrition. Finally, these structural alterations were noted to persist following a 3-week washout period and corresponding restoration of circadian HPA rhythmicity. These studies suggest that prolonged disruptions in adrenocortical functioning may be sufficient to induce enduring regressive structural and functional alterations in the mPFC. J. Comp. Neurol. 524:3729-3746, 2016. © 2016 Wiley Periodicals, Inc.
Competing Interests: The authors declare no competing financial interests.
(© 2016 Wiley Periodicals, Inc.)
Databáze: MEDLINE
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