Imipramine Ameliorates Depressive Symptoms by Blocking Differential Alteration of Dendritic Spine Structure in Amygdala and Prefrontal Cortex of Chronic Stress-Induced Mice
Yea-Hyun Leem1,†, Sang-Sun Yoon1,† and Sangmee Ahn Jo1,2,*
1Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan 31116, Republic of Korea
2Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Republic of Korea
E-mail: smahn@dankook.ac.kr
Tel: +82-41-550-1433, Fax: +82-41-550-7839
The first two authors contributed equally to this work.
Received: September 17, 2019; Revised: December 2, 2019; Accepted: December 11, 2019; Published online: February 7, 2020.
© The Korean Society of Applied Pharmacology. All rights reserved.

Abstract
Previous studies have shown disrupted synaptic plasticity and neural activity in depression. Such alteration is strongly associated with disrupted synaptic structures. Chronic stress has been known to induce changes in dendritic structure in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), but antidepressant effect on structure of these brain areas has been unclear. Here, the effects of imipramine on dendritic spine density and morphology in BLA and mPFC subregions of stressed mice were examined. Chronic restraint stress caused depressive-like behaviors such as enhanced social avoidance and despair level coincident with differential changes in dendritic spine structure. Chronic stress enhanced dendritic spine density in the lateral nucleus of BLA with no significant change in the basal nucleus of BLA, and altered the proportion of stubby or mushroom spines in both subregions. Conversely, in the apical and basal mPFC, chronic stress caused a significant reduction in spine density. The proportion of stubby or mushroom spines in these subregions overall reduced while the proportion of thin spines increased after repeated stress. Interestingly, most of these structural alterations by chronic stress were reversed by imipramine. In addition, structural changes caused by stress and blocking the changes by imipramine were corelated well with altered activation and expression of synaptic plasticity-promoting molecules such as phospho-CREB, phospho-CAMKII, and PSD-95. Collectively, our data suggest that imipramine modulates stress-induced changes in synaptic structure and synaptic plasticity-promoting molecules in a coordinated manner although structural and molecular alterations induced by stress are distinct in the BLA and mPFC.
Keywords: Depression, Dendritic spine, Basolateral amygdala, Medial prefrontal cortex, CaMKII, CREB


This Article


Cited By Articles
  • CrossRef (0)

e-submission

Archives