Abstract: Patients with post-traumatic stress disorder (PTSD) tend to show signs of a relatively increased inflammatory state suggesting that activation of the immune system may contribute to the development of PTSD.
In the present study, we tested whether activation of the innate immune system can disrupt acquisition or recall of auditory fear extinction using an animal model of PTSD. Male adolescent rats received auditory fear conditioning in context A.
The next day, an intraperitoneal injection of lipopolysaccharide (LPS; 100 μg/kg) prior to auditory fear extinction in context B impaired acquisition and recall of extinction. LPS (100 μg/kg) given after extinction training did not impair extinction recall suggesting that LPS did not affect consolidation of extinction.
In contrast to cued fear extinction, contextual fear extinction was not affected by prior injection of LPS (100 μg/kg)…… […]