Pair-housing rats does not protect from behavioral consequences of an acute traumatic experience.

Abstract

Posttraumatic stress disorder (PTSD) is an extremely debilitating disease with a broad array of associated symptoms, making the disorder difficult to diagnose and treat. In humans, patients seem to benefit from group therapy or other means of promoting social behavior. To test these effects on our rodent model of PTSD, adult, male rats were housed in either single or pair conditions prior to and during an acute stressor to induce PTSD-like behaviors in these rats. Subsequently, rats were assessed for PTSD-like symptoms to determine the effect of social housing on stress-induced phenotypes. Posttrauma phenotypes, including enhanced fear conditioning and anxiety-related behavior, persisted regardless of the animal's housing condition. It is possible that any housing driven improvements to stress-induced phenotypes would require longer periods of pair housing than were used in these experiments. Although PTSD patients show improved health outcomes following social interaction or group therapy, the fear and anxiety phenotypes seen following an acute stressor in an animal model of the disease endured despite an animal's housing condition.

Refinement of the stress-enhanced fear learning model of post-traumatic stress disorder: a behavioral and molecular analysis

“…Furthermore, SEFLsusceptible rats showed impaired extinction learning and impaired extinction memory retention, compared to SEFL-resilient rats with the same massed shock experience. Our finding that the SEFLsusceptible phenotype can be observed in group-housed rats extends a previous report that pairhousing animals does not protect against the development of the SEFL phenotype 28 and a recent report that group-housed animals are susceptible to a restraint-stress-based SEFL procedure 33 . Thus, group housing appears to be a potential refinement to the SEFL procedure.…”

“…Manipulation of housing conditions may represent another potential refinement of the SEFL procedure. Although rats undergoing the SEFL procedure are usually housed in social isolation [14][15][16][17]21 , the SEFL-susceptible phenotype has recently been demonstrated in rats that had been pair-housed throughout the procedure 28 . Thus, despite group-housing reducing the impact of stress in both rats 29,30 and mice 31 , the SEFL-susceptible phenotype appears to be sufficiently robust that it can be observed despite the potential for social buffering offered by group housing (see ref 32 for review).…”

Examining mGlu5 Receptor Availability as a Predictor of Vulnerability to PTSD: An [18F]FPEB and PET Study in Male and Female Rats

“…However, single housing can be considered a mild stressor, and a systematic evaluation of single versus pair-housing during the SEFL procedure was found to not influence behavior of either control or FE animals. 50 Therefore, group housing is an option that could be considered in future work and could additionally be used to examine possible sex-differences. Despite these caveats the strengths of this study include the prospective design, which allowed us to make statements on the predictive nature of mGlu5 availability and the directionality of relationships with PTSD susceptibility; the use of in vivo PET measurements which mirror the methodology used in human populations, making the findings here more immediately translatable to clinical findings; inclusion of both male and female rats and consideration of the main and interaction effects of sex for all analyses.…”

Dissociation in Effective Treatment and Behavioral Phenotype Between Stress-Enhanced Fear Learning and Learned Helplessness

“…With this stress volume, animals fail to exhibit escape latency deficits (Minor et al, 1994c), though it should be noted that this study used tailshock, not footshock. While one study did show an effect of shock on float time in the forced swim test (Perusini et al, 2016), this effect has subsequently failed to replicate (Tribble and Fanselow, 2019). Interestingly, the behavioral effects of the SEFL stress have been shown to persist for several months (Rau and Fanselow, 2009).…”

“…In the majority of stress models, animals are singly housed, as pair-housed animals often show decreased behavioral effects of stress (Liu et al, 2013). However, a series of studies aimed at probing the effects of single vs. pair-housing animals showed no significant effects in eliminating the SEFL phenotype (Tribble and Fanselow, 2019).…”