Corticosterone in the ventral hippocampus differentially alters accumbal dopamine output in drug-naive and amphetamine-withdrawn rats

NEUROPHARMACOLOGY

卷:165

Article

Bray, Brenna¹  Clement, Kaci A.¹  Bachmeier, Dana¹  Weber, Matthew A.^1,4  Forster, Gina L.^1,2,3 

[1] Univ South Dakota, Sanford Sch Med, Ctr Brain & Behav Res, Div Basic Biomed Sci, 414 E Clark St, Vermillion, SD 57069 USA

[2] Univ Otago, Dept Anat, POB 56, Dunedin 9054, New Zealand

[3] Univ Otago, Brain Hlth Res Ctr, POB 56, Dunedin 9054, New Zealand

[4] Iowa Neurosci Inst, Dept Neurol, Pappajohn Biomed Discovery Bldg,169 Newton Rd, Iowa City, IA 52242 USA

关键词: Psychostimulant withdrawal;    Ventral hippocampus;    Corticosterone;    Nucleus accumbens shell;    Dopamine;    Glucocorticoid receptors;   

DOI  :  10.1016/j.neuropharm.2019.107924

来源: Elsevier

【 摘 要 】

Dysregulation in glucocorticoid stress and accumbal dopamine reward systems can alter reward salience to increase motivational drive in control conditions while contributing to relapse during drug withdrawal. Amphetamine withdrawal is associated with dysphoria and stress hypersensitivity that may be mediated, in part, by enhanced stress-induced corticosterone observed in the ventral hippocampus. Electrical stimulation of the ventral hippocampus enhances accumbal shell dopamine release, establishing a functional connection between these two regions. However, the effects of ventral hippocampal corticosterone on this system are unknown. To address this, a stress-relevant concentration of corticosterone (0.24ng/0.5 mu L) or vehicle were infused into the ventral hippocampus of urethane-anesthetized adult male rats in control and amphetamine withdrawn conditions. Accumbal dopamine output was assessed with in vivo chronoamperometry. Corticosterone infused into the ventral hippocampus rapidly enhanced accumbal dopamine output in control conditions, but produced a biphasic reduction of accumbal dopamine output in amphetamine withdrawal. Selectively blocking glucocorticoid-, mineralocorticoid-, or cytosolic receptors prevented the effects of corticosterone. Overall, these results suggest that the ability of corticosterone to alter accumbal dopamine output requires cooperative activation of mineralocorticoid and glucocorticoid receptors in the cytosol, which is dysregulated during amphetamine withdrawal. These findings implicate ventral hippocampal corticosterone in playing an important role in driving neural systems involved in positive stress coping mechanisms in healthy conditions, whereas dysregulation of this system may contribute to relapse during withdrawal.

【 授权许可】

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