Abstract
The purpose of the current project was to examine if the innate behavioral reactivity of rodents to an aversive stimulus relates to the level of fear observed in a Pavlovian fear conditioning paradigm. The aim to study innate behavioral reactivity and level of fear is based on a line of research with human subjects suggesting that inherent physiological and behavioral responses could predict the level at which an individual learns about aversive stimuli. Furthermore, individuals diagnosed with post-traumatic stress disorder, a serious mental illness affecting roughly 6% of the general population, are found to have significant differences in how they learn about aversive stimuli and have related change s in physiological and behavioral reactivity compared to healthy adults. Here, we used the time to first ultrasonic vocalization, a social communication indicating positive and negative states in rodents, as a measure of behavioral reactivity and indication of innate fearfulness (anxiety group) during presentations of aversive stimuli. Preliminary analysis showed significant differences in freezing levels between rodent anxiety profiles during fear conditioning. Although further analysis is needed, current results demonstrate that the level of cue-induced fear during testing is not significantly different among anxiety groups. However, additional analyses are underway comparing subgroups of animals based on surgical manipulation and type of cue.