Stereological Study on the Positive Effect of Running Exercise on the Capillaries in the Hippocampus in a Depression Model.

Linmu Chen,Chuanxue Tan,Chunni Zhou,Yi Zhang,Feifei Wang,Yong Tang,Lin Jiang,Yuan Gao,Chunxia Huang

doi:10.3389/fnana.2017.00093

Abstract

Running exercise is an effective method to improve depressive symptoms when combined with drugs. However, the underlying mechanisms are not fully clear. Cerebral blood flow perfusion in depressed patients is significantly lower in the hippocampus. Physical activity can achieve cerebrovascular benefits. The purpose of this study was to evaluate the impacts of running exercise on capillaries in the hippocampal CA1 and dentate gyrus (DG) regions. The chronic unpredictable stress (CUS) depression model was used in this study. CUS rats were given 4 weeks of running exercise from the fifth week to the eighth week (20 min every day from Monday to Friday each week). The sucrose consumption test was used to measure anhedonia. Furthermore, stereological methods were used to investigate the capillary changes among the control group, CUS/Standard group and CUS/Running group. Sucrose consumption significantly increased in the CUS/Running group. Running exercise has positive effects on the capillaries parameters in the hippocampal CA1 and DG regions, such as the total volume, total length and total surface area. These results demonstrated that capillaries are protected by running exercise in the hippocampal CA1 and DG might be one of the structural bases for the exercise-induced treatment of depression-like behavior. These results suggest that drugs and behavior influence capillaries and may be considered as a new means for depression treatment in the future.

Highlights

Depressive disorder is widely distributed in the population (Kessler et al, 2003), as it is the main reason of disability worldwide (Menard et al, 2016)
Our study displayed that the preference of sucrose consumption in chronic unpredictable stress (CUS)/Running group was higher than that in the CUS/Standard group and reached normal levels when compared with the control group
Our study showed that the preference of sucrose consumption and the open-field score were decreased significantly in the CUS group after 4 weeks, which indicated that the depression model was established successfully

Summary

Introduction

Depressive disorder is widely distributed in the population (Kessler et al, 2003), as it is the main reason of disability worldwide (Menard et al, 2016). Common antidepressant drugs act on monoamine neurotransmitters because of their significant role in the pathogenesis of depression. To provide a new treatment for depression, it is important to further study the pathogenesis of depression. Greist et al (1979) revealed that aerobic running is a treatment for moderate depression. Some studies revealed that physical exercise might be a safe and effective antidepressant therapy in late-life major depression patients (Belvederi Murri et al, 2015) and in rats and mice with depression-like behavior (Lee et al, 2013; Eldomiaty et al, 2017). The mechanisms underlying the antidepressant effect of running exercise are not fully understood

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