The Integration of Depressive Behaviors and Cardiac Dysfunction During an Operational Measure of Depression: Investigating the Role of Negative Social Experiences in an Animal Model : Psychosomatic Medicine

Journal Logo

Advanced Search
Original Articles

The Integration of Depressive Behaviors and Cardiac Dysfunction During an Operational Measure of Depression

Investigating the Role of Negative Social Experiences in an Animal Model

Grippo, Angela J. PhD; Moffitt, Julia A. PhD; Sgoifo, Andrea PhD; Jepson, Amanda J. BS; Bates, Suzanne L. BA; Chandler, Danielle L. BS; McNeal, Neal BS; Preihs, Kristin BA

Author Information

From the Department of Psychology (A.J.G., S.L.B., D.L.C., N.M., K.P.), Northern Illinois University, DeKalb, Illinois; Department of Physiology and Pharmacology (J.A.M., A.J.J.), Des Moines University, Des Moines, Iowa; and Stress Physiology Lab (A.S.), Department of Evolutionary and Functional Biology, University of Parma, Parma, Italy.

Address correspondence and reprint requests to Angela J. Grippo, PhD, Department of Psychology, Northern Illinois University, PM 357, DeKalb, IL 60115. E-mail: [email protected]

This research was supported by the National Institutes of Health (Grants MH73233 and MH77581).

Received for publication November 10, 2011; revision received January 27, 2012.

Psychosomatic Medicine 74(6):p 612-619, July/August 2012. | DOI: 10.1097/PSY.0b013e31825ca8e5

Abstract

Objective 

There is a bidirectional association between depression and cardiovascular disease. The neurobiological mechanisms underlying this association may involve an inability to cope with disrupted social bonds. This study investigated in an animal model the integration of depressive behaviors and cardiac dysfunction after a disrupted social bond and during an operational measure of depression, relative to the protective effects of intact social bonds.

Methods 

Depressive behaviors in the forced swim test and continuous electrocardiographic parameters were measured in 14 adult, female socially monogamous prairie voles (rodents), after 4 weeks of social pairing or isolation.

Results 

After social isolation, animals exhibited (all values are mean ± standard error of the mean; isolated versus paired, respectively) increased heart rate (416 ± 14 versus 370 ± 14 bpm, p < .05) and reduced heart rate variability (3.3 ± 0.2 versus 3.9 ± 0.2 ln(ms2)). During the forced swim test, isolated animals exhibited greater helpless behavior (immobility = 106 ± 11 versus 63 ± 11 seconds, p < .05), increased heart rate (530 ± 22 versus 447 ± 15 bpm, p < .05), reduced heart rate variability (1.8 ± 0.4 versus 2.7 ± 0.2 ln(ms2), p < .05), and increased arrhythmias (arrhythmic burden score = 181 ± 46 versus 28 ± 12, p < .05).

Conclusions 

The display of depressive behaviors during an operational measure of depression is coupled with increased heart rate, reduced heart rate variability, and increased arrhythmias, indicative of dysfunctional behavioral and physiological stress coping abilities as a function of social isolation. In contrast, social pairing with a sibling is behaviorally protective and cardioprotective. The present results can provide insight into a possible social mechanism underlying the association between depression and cardiovascular disease in humans.

Abbreviations 

ANOVA = analysis of variance

DSI = Data Sciences International

ECG = electrocardiographic

FST = forced swim test

HR = heart rate

RSA = respiratory sinus arrhythmia

SDNN = standard deviation of normal-to-normal intervals

SEM = standard error of the mean

Copyright © 2012 by American Psychosomatic Society

Full Text Access for Subscribers:

Not a Subscriber?

Buy
Request Permissions

You can read the full text of this article if you:

Access through Ovid