A stress-resistant rat model was introduced. SPORTS (Spontaneously-Running-Tokushima-Shikoku) rats showed significantly shorter time of immobility in the forced swim test compared to control Wister rats. Increase norepinephrine concentration secondary to decreased activity of monoamine oxidase A (MAOA) in hippocampus was observed in this model rats. This model rats are considered to be useful f...

BACKGROUND We have examined the effects of nicotine pretreatment on dopaminergic and behavioral responses to conditioned fear stress in the rat. METHODS Rats were pretreated daily with saline or nicotine for 20 days then challenged with nicotine or saline on day 21. Animals were trained in a classical conditioned fear paradigm. Dopamine utilization in the medial prefrontal cortex and nucleus ...

BACKGROUND The opioid peptide beta-endorphin (beta-E) is synthesized and released in response to stressful stimuli as well as acute alcohol administration. The release of beta-E following exposure to an inescapable aversive situation may mediate behaviors that contribute to allostasis of the stress response. The present study examines the effects of beta-E on immobility in assays involving ines...

Rat pups become immobile and analgesic when exposed to an adult male rat. The aim of this study was to determine whether these reactions are under the control of endogenous opioids and to determine the role of the midbrain periaqueductal gray (PAG), which mediates stress-induced immobility and analgesia in adult animals. In Experiment 1, 14-day-old rats were injected systemically with the gener...

Whether prenatal stress (PNS) and gonadal hormones may influence depressive behavior of rats in the forced swim test was investigated. In Experiment I, adult diestrous female rats had increased immobility, which is indicative of depression, but did not show any significant difference in the duration of struggling compared to intact adult males. In Experiment 2, the behavior of adult intact, cas...

SART (specific alternation of rhythm in temperature) stress is known to cause anxiety-like behavior in mice/rats in several anxiety-related behavioral tests. In the present study, we investigated possible roles for corticotropin-releasing factor (CRF) and glucocorticoids in SART stress-induced anxiety-like behavior in two different anxiety-related behavioral tests. In the forced swimming test, ...

Introduction: As stress affects the brain both physiologically and chemically, researchers try to find novel anti-stress compounds with beneficial therapeutic effects. In this regard, the effect of stress and its modulation by Morin hydrate was studied using different acute models in mice. Methods: The models employed were anoxic tolerance, swimming endurance, and acute restraint test. Morin h...

Traumatization, the operative infliction of a trauma/ traumatic event, may be described as the process(es) through which the criteria of posttraumatic stress disorder (PTSD) are achieved. Trauma or a traumatic event stems from an overwhelming/excruciating bombardment of extreme stress that exceeds individuals' ability to cope, or integrate the cognitive-climate involved with that or those exper...

Oxidative stress is considered to be a mechanism of major depression. Pycnogenol (PYC) is a natural plant extract from the bark of Pinus pinaster Aiton and has potent antioxidant activities. We studied the ameliorative effect of PYC on depression-like behavior in chronic corticosterone- (CORT-) treated mice for 20 days. After the end of the CORT treatment period, PYC (0.2 mg/mL) was orally admi...