Limits...
Influence of daily social stimulation on behavioral and physiological outcomes in an animal model of PTSD.

Seetharaman S, Fleshner M, Park CR, Diamond DM - Brain Behav (2016)

Bottom Line: We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects.We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

View Article: PubMed Central - PubMed

Affiliation: Department of PsychologySt. Ambrose UniversityDavenportIowa52803; Center for Preclinical and Clinical Research on PTSDUniversity of South FloridaTampaFlorida33620.

ABSTRACT

Introduction: We have shown in previous work that acute episodes of predator exposure occurring in the context of chronic social instability produced PTSD-like sequelae in rats. Our animal model of PTSD contained two components: (1) acute trauma, immobilization of rats in close proximity to a cat twice in 10 days, and (2) chronic social instability, 31 days of randomized housing of cage cohorts. Here we tested the hypothesis that daily social stimulation would block the development of the PTSD-like sequelae.

Methods: Beginning 24 h after the first cat exposure, adult male rats were given our established PTSD model, alone or in conjunction with daily social stimulation, in which all rats within a group interacted in a large apparatus for 2 h each day for the final 30 days of the PTSD regimen. All behavioral, for example, anxiety, memory, startle testing, and physiological assessments, for example, body growth, organ weights, and corticosterone levels, took place following completion of the psychosocial stress period.

Results: Daily social stimulation blocked the expression of a subset of PTSD-like effects, including predator-based cued fear conditioning, enhanced startle response, heightened anxiety on the elevated plus maze and the stress-induced suppression of growth rate. We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.

Conclusions: Daily exposure of rats to a highly social environment blocked the development of a subset of trauma-induced sequelae, particularly fear-related outcomes. It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects. We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

No MeSH data available.


Related in: MedlinePlus

Startle response. There were no significant between‐group differences on acoustic startle response at the 90 and 100 dB stimulus intensity levels. At 110 dB, the No Social–Stress group exhibited a significant elevation in startle response relative to the other three groups. Data are presented as the mean startle response (Newtons) to the 90, 100, and 110 dB acoustic stimuli ± SEM. *P < 0.05 relative to all other groups at 110 dB stimulus intensity.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4834360&req=5

brb3458-fig-0004: Startle response. There were no significant between‐group differences on acoustic startle response at the 90 and 100 dB stimulus intensity levels. At 110 dB, the No Social–Stress group exhibited a significant elevation in startle response relative to the other three groups. Data are presented as the mean startle response (Newtons) to the 90, 100, and 110 dB acoustic stimuli ± SEM. *P < 0.05 relative to all other groups at 110 dB stimulus intensity.

Mentions: There were no significant differences among groups on startle response magnitudes for the 90 and 100 dB acoustic stimuli. The responses to 110 dB revealed a significant main effect of social stimulation, F(1, 30) = 0.025, and a significant Stress × Social stimulation interaction, F(1, 28) = 12.76 (P < 0.05). Post hoc tests revealed that animals in the Stress/No Social group exhibited significantly greater startle responses than the other three groups at the 110 dB intensity (Fig. 4).


Influence of daily social stimulation on behavioral and physiological outcomes in an animal model of PTSD.

Seetharaman S, Fleshner M, Park CR, Diamond DM - Brain Behav (2016)

Startle response. There were no significant between‐group differences on acoustic startle response at the 90 and 100 dB stimulus intensity levels. At 110 dB, the No Social–Stress group exhibited a significant elevation in startle response relative to the other three groups. Data are presented as the mean startle response (Newtons) to the 90, 100, and 110 dB acoustic stimuli ± SEM. *P < 0.05 relative to all other groups at 110 dB stimulus intensity.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834360&req=5

brb3458-fig-0004: Startle response. There were no significant between‐group differences on acoustic startle response at the 90 and 100 dB stimulus intensity levels. At 110 dB, the No Social–Stress group exhibited a significant elevation in startle response relative to the other three groups. Data are presented as the mean startle response (Newtons) to the 90, 100, and 110 dB acoustic stimuli ± SEM. *P < 0.05 relative to all other groups at 110 dB stimulus intensity.
Mentions: There were no significant differences among groups on startle response magnitudes for the 90 and 100 dB acoustic stimuli. The responses to 110 dB revealed a significant main effect of social stimulation, F(1, 30) = 0.025, and a significant Stress × Social stimulation interaction, F(1, 28) = 12.76 (P < 0.05). Post hoc tests revealed that animals in the Stress/No Social group exhibited significantly greater startle responses than the other three groups at the 110 dB intensity (Fig. 4).

Bottom Line: We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects.We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

View Article: PubMed Central - PubMed

Affiliation: Department of PsychologySt. Ambrose UniversityDavenportIowa52803; Center for Preclinical and Clinical Research on PTSDUniversity of South FloridaTampaFlorida33620.

ABSTRACT

Introduction: We have shown in previous work that acute episodes of predator exposure occurring in the context of chronic social instability produced PTSD-like sequelae in rats. Our animal model of PTSD contained two components: (1) acute trauma, immobilization of rats in close proximity to a cat twice in 10 days, and (2) chronic social instability, 31 days of randomized housing of cage cohorts. Here we tested the hypothesis that daily social stimulation would block the development of the PTSD-like sequelae.

Methods: Beginning 24 h after the first cat exposure, adult male rats were given our established PTSD model, alone or in conjunction with daily social stimulation, in which all rats within a group interacted in a large apparatus for 2 h each day for the final 30 days of the PTSD regimen. All behavioral, for example, anxiety, memory, startle testing, and physiological assessments, for example, body growth, organ weights, and corticosterone levels, took place following completion of the psychosocial stress period.

Results: Daily social stimulation blocked the expression of a subset of PTSD-like effects, including predator-based cued fear conditioning, enhanced startle response, heightened anxiety on the elevated plus maze and the stress-induced suppression of growth rate. We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.

Conclusions: Daily exposure of rats to a highly social environment blocked the development of a subset of trauma-induced sequelae, particularly fear-related outcomes. It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects. We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

No MeSH data available.


Related in: MedlinePlus