Data repository is unknown. Contact the manager to learn where to access the data.
Jun 18, 2018
Stress effects on fear learning
Post-traumatic stress disorder (PTSD) is a highly heterogeneous disorder, with not all patients experiencing the same types or intensity of symptoms. PTSD is also frequently comorbid with alcohol abuse, further complicating treatment. However, the biological mechanisms that underlie different PTSD symptoms, and the factors that promote susceptibility or resilience to the disorder, remain unclear. Rodent models of PTSD offer a valuable tool for probing these biological mechanisms. This study investigates how the variability observed in PTSD is captured by Stress-Enhanced Fear Learning (SEFL), a rodent model of PTSD developed to recapitulate critical aspects of the disorder including a very long-term sensitization of fear learning caused by an acute stressor.
The key feature of the SEFL model is that following exposure to a trauma (15 footshocks over 90 minutes), rats will show a heightened fear response to a mild stressor (a single footshock in a novel context). While almost all animals show heightened fear learning following this procedure, using a less intense trauma (4 footshocks over 90 minutes) produces considerably more variability, with only a subset of animals showing enhanced fear learning. This study is investigating how baseline anxiety and alcohol consumption, sex and trauma intensity interact to produce changes in fear learning, anxiety and alcohol consumption following trauma. We have found that the more intense trauma produced greater increases in fear learning, generalization and anxiety compared to the less intense trauma. While males and females did not differ on assessments of fear learning, females did show increased baseline alcohol consumption and decreased anxiety following trauma relative to males. Lastly, preliminary evidence indicates that animals that are show sensitized fear learning following the less intense trauma also show a constellation of other behavioral changes, including increased fear generalization, anxiety and alcohol consumption.
|Number of Subjects||80|