Single prolonged stress impairs social and object novelty recognition in rats

Abstract

Posttraumatic stress disorder (PTSD) results from exposure to a traumatic event and manifests as re-experiencing, arousal, avoidance, and negative cognition/mood symptoms. Avoidant symptoms, as well as the newly defined negative cognitions/mood, are a serious complication leading to diminished interest in once important or positive activities, such as social interaction; however, the basis of these symptoms remains poorly understood. PTSD patients also exhibit impaired object and social recognition, which may underlie the avoidance and symptoms of negative cognition, such as social estrangement or diminished interest in activities. Previous studies have demonstrated that single prolonged stress (SPS), models PTSD phenotypes, including impairments in learning and memory. Therefore, it was hypothesized that SPS would impair social and object recognition memory. Male Sprague Dawley rats were exposed to SPS then tested in the social choice test (SCT) or novel object recognition test (NOR). These tests measure recognition of novelty over familiarity, a natural preference of rodents. Results show that SPS impaired preference for both social and object novelty. In addition, SPS impairment in social recognition may be caused by impaired behavioral flexibility, or an inability to shift behavior during the SCT. These results demonstrate that traumatic stress can impair social and object recognition memory, which may underlie certain avoidant symptoms or negative cognition in PTSD and be related to impaired behavioral flexibility.

Brain-derived neurotrophic factor heterozygous mutant rats show selective cognitive changes and vulnerability to chronic corticosterone treatment

“…We also observed a CORT-induced reduction in novel object interactions for both genotypes. This is in line with findings by Eagle et al (2013) who have shown that chronic stress induces impairments in novel object recognition in rats.…”

Systemic lipopolysaccharide administration impairs retrieval of context–object discrimination, but not spatial, memory: Evidence for selective disruption of specific hippocampus-dependent memory functions during acute neuroinflammation

“…However, in the present study we did not observe any LPS-induced deficits in the water maze, suggesting there was not a debilitating stress-immune interaction due to single-housing. Additionally, while COD and NOR had virtually the same experiment design and task demands of one another, systemic LPS administration only produced a deficit in COD but not NOR, which has previously been shown to be impaired by different stressors (Baker and Kim, 2002; Eagle et al, 2013). Therefore, since we did not observe any LPS-induced memory retrieval deficits in NOR or the water maze, it is unlikely that stress due to single-housing exacerbated the effects of systemic LPS administration.…”

Disruption of social cognition in the sub-chronic PCP rat model of schizophrenia: Possible involvement of the endocannabinoid system

“…Interestingly, this selective impairment of social novelty preference has been reported across a broad range of animal models of schizophrenia (Kaminitz et al 2014; O'Tuathaigh et al 2007; Shimamoto et al 2014; Zoubovsky et al 2015, but O'Tuathaigh et al 2010a). Eagle and co-workers (Eagle et al 2013) proposed that this selective impairment might be related to the differences between sensation-seeking versus novelty-seeking behaviors, the latter requiring to recall and recognize a familiar versus a novel object. Therefore, a major challenge in the interpretation of our findings is to understand whether the lack of preference for social novelty is caused by a social recognition/memory deficit or not.…”