Sex Differences in Stressor Controllability in Long Evans Rats

Nate Bosnian, Dr. J. Alex Grizzell, and Dr. Michael Saddoris, Department of Psychology and Neuroscience, Center for Neuroscience Research, University of Colorado at Boulder, Boulder, CO, 80309

The degree of behavioral control that an organism has learned to exert over a stressor has repeatedly been shown to bidirectionally modulate the impacts of future stressors. Specifically, uncontrollable stress produces numerous depression-like behavioral and neural outcomes in Sprague-Dawley (SD) rats, while behavioral control over a stressful event can produce stress resilience. However, these effects appear to be limited to male, but not female, SD rats. Currently, it is unknown whether these sex-linked effects of behavioral control extend to different strains of rats.  To test this, this study investigates stressor controllability effects in male and female Long-Evans (LE) rats. As in previous studies, both an Escapable Shock (ES) and Inescapable Shock (IS) rat are fitted into a chamber where both unpredictably receive tailshocks. The ES rat can terminate the shock by rotating a wheel in the chamber for both animals, while the IS rat’s actions have no consequence. Thus, both animals receive identical shocks, but only the ES rat has control over the stressful event. Preliminary findings suggest subtle differences in how stressor controllability is mediated in SD and LE males. Following controllable (ES) or uncontrollable (IS) stress, LE rats of both sexes will be observed in a juvenile social exploration (JSE) task as well as a defensive burial task (DBT). In the JSE, subjects’ sniffing, allogrooming, agonistic, and nonsocial behavior of same-sexed, novel, intruding juveniles will be compared across stress and sex conditions. In the DBT, similar comparisons will be made regarding latency and depth of burying a shock probe with available bedding. We predict that we will observe sex differences in these behaviors, but that LE female rats will exhibit some differences between controllable and uncontrollable stress conditions that were not seen in previous studies on SD rats.

Additional Abstract Information

Presenter: Nate Bosnian

Institution: University of Colorado at Boulder

Type: Poster

Subject: Biology

Status: Approved

Time and Location

Session: Poster 2
Date/Time: Mon 3:00pm-4:00pm
Session Number: 2670