Different effects of tianeptine pretreatment in rats exposed to acute stress and repeated severe stress

Abstract

In this study we aim to discuss the relationship between stress and learning and emotionality in an experimental model using two different stress conditions: acute stress (single restraint stress for 20 min) and repeated severe stress (6-h daily restraint for 21 days). We studied the effects of tianeptine, which has been suggested to have anxiolytic and cognition-enhancing effects under stressful conditions. After acute stress, the increase in the duration of immobility (F = 5.753 and 3.664) in the open field and holeboard tests and the decrease in rearing (F = 3.891) in the holeboard test were significant when compared to controls (P < 0.05). Results for repeated severe stress showed that in both the open field and holeboard tests the decrease in rearing (F = 4.494 and 4.530, respectively), increase in the duration of immobility (F = 6.069 and 4.742, respectively) and decrease in head dips (F = 4.938) in the holeboard test were statistically significant (P < 0.05). The group pretreated with tianeptine showed no significant difference from controls for either acute or repeated severe stress conditions. In the Morris water maze test, acute stress led to a prolongation of average escape latency, which indicated a spatial learning deficit. Treatment with tianeptine prior to acute stress prevented this spatial deficit. Repeated severe stress also led to spatial learning deficits in rats, but this deficit was not prevented by treatment with tianeptine. Our study demonstrates that pretreatment with tianeptine had different effects on stress-induced spatial learning deficits under acute and repeated stress conditions, while the effects on emotionality and anxiety-like behavior were similar. The mechanisms implicated in stress-induced emotional and memory deficits will be discussed.

Chronic restraint stress impairs sociability but not social recognition and spatial memoryin C57BL/6J mice

“…Our results also did not appear to be confounded either by motivational or motor factors as indicated by no significant different in the distance travelled and swim speed during the acquisition phase between the control and stressed groups. Our results during the probe trial supported previous studies which showed that no significant difference was observed between control and stressed groups, which indicates that chronic stress did not affect spatial memory [14, 16, 36]. However, our results contradicted studies that showed chronic stress either impaired [1, 18, 20] or facilitated spatial memory [11] in the water maze test.…”

A critical evaluation of the activity-regulated cytoskeleton-associated protein (Arc/Arg3.1)'s putative role in regulating dendritic plasticity, cognitive processes, and mood in animal models of depression

“…The available data suggest that acute restraint stress induces mixed effects in hippocampus-dependent learning and memory tasks, with most labs showing significant impairments in tasks such as the Morris water maze (Kasar et al, 2009 ; Buechel et al, 2014 ) and others showing significant improvements (Zheng et al, 2007 ). Performance in cognitive tasks that are thought to depend on the extended hippocampal network, such as novel object recognition (Aggleton and Brown, 2005 ; Barker and Warburton, 2011 ) are also negatively affected by acute stress (Guercio et al, 2014 ; Vargas-Lopez et al, 2015 ).…”

“…Additionally, female rodents subjected to 6 h restraint stress per day for 21 days performed significantly better in the same radial arm maze task (Bowman et al, 2009 ). However, in the Morris water maze and Barnes maze, chronic stress universally seems to impair performance (Kasar et al, 2009 ; Bian et al, 2012 ; Tian et al, 2013 ; Rinwa and Kumar, 2014 ; Huang et al, 2015 ; Trofimiuk and Braszko, 2015 ). Thus, although there are some complexities in terms of how chronic stress modulates performance in hippocampus-dependent cognitive tests, on average stress seems to impair performance, at least in male subjects.…”