Stress forced swimming

Behavioral alterations induced by stressful experiences frequently include increased anxiety-related behavior. Accordingly, anxiety has been hypothesized to play a role in stress-coping behavior (Ferre et al. 1994). The most regularly used tests for stress-coping behavior is the so-called forced swim test, which has been developed by Porsolt et al. (1977) as a behavioral paradigm to identify compounds with antidepressant efficacy in humans Mice or rats are forced to... 

West PA (1990) Neimobehavioral studies of forced swimming. The role of learning and memory in the forced swim test ProgNeimopsychopharmacol Biol Psychiatry 14 863-875 WUlner P (1997) Validity, reliability and utility of the chronic mild stress model of depression a 10-year review and evaluation. Psychopharmacology (Berl) 134 319-329 WUlner P, Muscat R, Papp M (1992) Chronic mUd stress-induced anhedonia a realistic animal model of depression. Neimosci Biobehav Rev 16 525-534 WUson JH (2000) A conspecific attenuates prolactin responses to open-field exposure in rats. Horm Behav 38 39-43... 

As a facet of anxiety-like behavior, 5-HTia receptor KO mice show genotype-dependent and background strain-unrelated increase in stress reactivity in two paradigms of behavioral despair, the forced swim and tail suspension tests... 

To assess the effects of forced swim stress on hippocampal serotoninergic neurotransmission and the role of CRH herein we performed a microdialysis study in rats. Rats were connected to a swivel system via a plastic collar around... 

Taken together, the data reviewed here show that forced swim stress induces a highly differentiated (putatively CRH-dependent) response in serotoniner-gic neurotransmission in higher brain structures, with the final outcome of the manipulation depending on the exact experimental design. Moreover, the dramatic CRH receptor-dependent increase in hippocampal 5-HT as observed... 

In humans, the antidepressant activity of NMDA receptor antagonists has not been evaluated extensively (Skohiick 1999). In animal models of depression, NMDA receptor antagonists have been reported to exert positive effects in most studies (Trullas 1997). This concerns mainly the forced swim test (Maj 1992 Moryl et al. 1993 PrzegaUnski et al. 1997) and stress-induced anhe-donia (Papp and Moryl 1994). Amantadine but not memantine was effective against reserpine-induced hypothermia (Moryl et al. 1993). In the forced swim test, both amino-adamantanes produced specific antidepressive-like activity (Moryl et al. 1993). 

Stogner KA, Holmes PV (2000) Neuropeptide-Y exerts antidepressant-like effects in the forced swim test in rats. Eur J Pharmacol 387 R9-R10 Stout SC, Owens MJ, Nemeroff CB (2002) Regulation of corticotropin-releasing factor neuronal systems and hypothalamic-pituitary-adrenal axis activity by stress and chronic antidepressant treatment. J Pharmacol Exp Ther 300 1085-1092 StrOhle A, Jahn H, Montkowski A, Liebsch G, Boll E, Landgraf R, Holsboer F, Wiedemann K (1997) Central and peripheral administration of atriopeptin is anxiolytic in rats. Neuroendocrinology 65 210-215... 

Strekalova, T., Spanagel, R., Bartsch, D., Henn, F. A. and Gass, P. (2004) Stress-induced anhedonia in mice is associated with deficits in forced swimming and exploration. Neuropsychopharmacology 29, 2007-2017. 

Specifically, these studies found that 5-HT1A-R null animals showed increased anxiety-like behavior in the open field, elevated plus maze, elevated zero maze, and novel object tests. 5-HT1A-R KOs were also less immobile in the forced swim and tail suspension tests, the same response induced in these tests by antidepressant drugs. However, it is unclear whether this decreased immobility truly reflects an antidepressant-like coping reaction mediated by increased 5-HT transmission or whether it simply reflects an increased stress response in these anxiety-prone mutant mice (12). 

This interpretation of immobility in the forced swim test has been challenged numerous times since its creation. It was proposed that these behaviors are not emotional responses to stressful situations, but a learned response that occurs during extended or between successive swim exposures. The learned response might be considered an adaptive strategy used to conserve energy required for swimming and survival [for review see 4], Based on these interpretations, it was suggested that antidepressants may decrease immobility by... 

Several animal models of depressive disorders have been studied, and space does not permit detailed review of these findings. Animal models of depression have fallen into three general categories Stress induced, ethologically relevant, and genetic (Machado-Vieira et al., 2004). Of the stress-indnced models, learned helplessness, chronic mild stress, and forced swim (behavioral despair) are best characterized (Willner and Mitchell, 2002). 

Forced-swim stress and behavioral despair test 4 t... 

Antidepressant activity. In two different studies, Pan et al. demonstrated that icariin, isolated from E. brevicornum, had an antide-pressant-like effect in the forced swimming test and tail suspension test in mice after oral administration for 21 and 7 days, respectively. The 21-day treatment also resulted in a decrease in the levels of MAO and serum CRF. Further investigation of its mechanism of action in rats showed that icariin reduced the serum levels of CRF, IL-6, and TNF-a resulting in the chronic mild stress model utilized in the study. ... 

Forcing the animal to swim is a powerful motivator and thereby induces a stable behavioral baseline, once the animal has experienced the escape platform. On the other hand, the situation represents a major stress, particularly if the animal has difficulty finding the escape platform on the first trial. When this happens, drug effects on emotional factors, for example behavioral despair (Porsolt et al. 1979) could confound interpretations in terms of leaming/memory. The random nature of the first discovery of the platform is therefore a factor which increases variability, whereas subsequent learning varies little from one occasion to the next and is more clearly interpretable. 

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