Abstract
An innovative animal model of posttraumatic stress disorder (PTSD) is proposed in which nonhabituation of the acoustic startle response is developed in rats subsequent to tailshock exposure. Subjects (n = 31) received 30 minutes of intermittent tail shock on 2 days followed by exposure to the tailshock apparatus on the third day. Compared to baseline startle reactions, 9 of 31 tailshock-exposed rats developed nonhabituation of startle response reactions during the subsequent 3 weeks of testing. No control rats developed nonhabituation of startle reactions over a similar time period. These data suggest that this system models useful aspects of clinical PTSD emphasizing nonhabituation of startle reactions as a dependent variable. The method consistently identifies a subgroup of rats that develop persistent nonhabituation of startle in response to a tailshock-stress paradigm.