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Stress relief by 'comfort food' in females

Egan, Ann
http://rave.ohiolink.edu/etdc/view?acc_num=ucin150998365465551

Abstract Details

2017, PhD, University of Cincinnati, Medicine: Neuroscience/Medical Science Scholars Interdisciplinary.
Many individuals increase their intake of tasty, high-calorie foods during times of stress. In turn, these palatable foods can reduce physiological and psychological measures of stress, a concept reflected in the term `comfort food.’ Obesity is one of the major public health issues facing the United States, and stress eating may be a contributing factor. Thus, investigating the mechanisms behind palatable food-mediated stress relief could provide important insights into treatments or prevention of obesity-related disorders. A limited sucrose intake (LSI) paradigm of palatable foods has been shown to reduce stress responses in male rats through a basolateral amygdala (BLA) mediated neurocircuit. However, women may be more prone to `comfort feeding’ than men, and these eating behaviors may fluctuate across the menstrual cycle. This suggests there may be sex differences in how palatable food affects stress responses. It is unknown if palatable foods reduce stress responses in female rats, and if the effects vary with estrous cycle. Therefore, we characterized the effects of limited sucrose intake on stress responses in female rats. We found that a history of LSI reduces HPA axis responsivity and behavioral anxiety; notably this stress blunting is estrous-cycle dependent. LSI only reduces stress responses during the proestrus/estrus (P/E) stage of the estrous cycle, and not the diestrus 1/diestrus 2 (D1/D2) stage. This suggests fluctuating levels of gonadal hormones may be interacting with palatable foods to modulate stress responses. We used traditional neuroanatomical methods and innovative mathematical modeling techniques to identify a potential neurocircuit underlying this cycle-specific stress relief. We found estrous cycle-specific effects of LSI in the BLA, central amygdala, and the bed nucleus of the stria terminalis. Furthermore, Bayesian modeling, which was used to analyze predicted relationships among multiple brain regions, indicated that during P/E LSI may be altering interactions with the nucleus accumbens, a region important for reward regulation. This potential neurocircuit underlying LSI stress blunting has both similarities and differences to the circuit hypothesized for male rats, suggesting LSI-mediated stress relief may be driven by slightly different mechanisms in female rats. Because the LSI-mediated stress relief was specific to the P/E stage of the estrous cycle when levels of gonadal hormones are higher, we investigated elevated estrogen as a possible mechanism behind this effect. Ovariectomized (OVX) female rats replaced with low levels of estrogen did not show blunted HPA axis responses after LSI, similar to intact D1/D2 rats. However, OVX female rats replaced with high levels of estrogen also did not show blunted HPA axis responses after LSI, in contrast to intact P/E rats. This suggests that higher levels of estrogen alone are not sufficient to mediate the estrous cycle-specific effects of LSI seen in female rats. Together, this work shows that limited sucrose intake reduces stress responses in female rats in a manner that depends on the estrous cycle. This indicates important sex differences in the interactions between stress, eating behaviors and gonadal hormones. This work has important implications for the treatment and prevention of obesity- and stress-related disorders.
Teresa Reyes, Ph.D. (Committee Chair)
James Herman, Ph.D. (Committee Member)
Brent Myers (Committee Member)
Matia Solomon, Ph.D. (Committee Member)
Yvonne Ulrich-Lai, Ph.D. (Committee Member)
188 p.
Neurology
stress; palatable food; sex differences; comfort food; sucrose; females

Recommended Citations

Citations

  • Egan, A. (2017). Stress relief by 'comfort food' in females [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin150998365465551

    APA Style (7th edition)

  • Egan, Ann. Stress relief by 'comfort food' in females. 2017. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin150998365465551.

    MLA Style (8th edition)

  • Egan, Ann. "Stress relief by 'comfort food' in females." Doctoral dissertation, University of Cincinnati, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin150998365465551

    Chicago Manual of Style (17th edition)

ucin150998365465551
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© 2017, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.