Hatano high- and low-avoidance (HAA and LAA) rats are separated by breeding from Sprague-Dawley rats by high versus low rates of avoidance responses in a shuttle-box task. In addition, compared to HAA rats, LAA rats show lower running-wheel activity, later sexual maturation, 5-day estrous cycling, lower sperm motility, more pronounced immunological reactions, and are generally less reactive to ...

Alzheimer's disease (AD) is the most common form of dementia in the elderly. For more effective therapy early diagnostic markers could be beneficial. Therefore we compared one year old rats with adults and examined if changes in possible brain markers of AD preceeded memory decline. We also tested if vasopressin-deficient animals were useful model of AD as vasopressin has well known positive ef...

The effect of the nootropic drug piracetam (100 mg/kg) on kindled seizures, kindling-induced learning deficits, and histological alterations due to changes in central excitability was investigated in Wistar rats. The animals were kindled by repeated i.p. injections of an initially subconvulsive dose of pentylenetetrazol (PTZ). As a control, piracetam or physiological saline was given 60 minutes...

Trans-resveratrol is a phenolic compound enriched in polygonum cuspidatum and has diverse biological activities. There is only limited information about the antidepressant-like effect of trans-resveratrol. The present study investigated whether trans-resveratrol has antidepressant-like activity in rats exposed to chronic stress by using two behavioral tasks, shuttle box and sucrose preference t...

Although much has been learned about the role of the amygdala in Pavlovian fear conditioning, relatively little is known about an involvement of this structure in more complex aversive learning, such as acquisition of an active avoidance reaction. In the present study, rats with a pretraining injection of the N-methyl-D-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonopentanoic acid (AP...

The present study evaluated the long-lasting effects of neonatal handling (NH; administered during the first 21 days of life) on unlearned and learned anxiety-related responses in inbred Roman High- (RHA-I) and Low-avoidance (RLA-I) rats. To this aim, untreated and neonatally-handled RHA-I and RLA-I rats of both sexes were tested in the following tests/tasks: a novel object exploration (NOE) te...

Although the etiology of clinical depression is unknown, women are more likely to suffer from major depressive disorder than men. In addition, in some women, there is a clear association between depression and specific phases of the menstrual cycle. Surprisingly little research has examined gender differences and the influences of the estrous cycle in this and other animal behavioral models of ...

Hippocampal granule neurons that are newly formed during adulthood might be involved in learning and memory processes. Experimental data suggest that only hippocampus-dependent learning tasks stimulate neurogenesis. To further address this issue, the effects of active shock avoidance (ASA) learning on hippocampal progenitor proliferation and survival of newly formed cells were investigated. ASA...

The high- and low-avoidance animal (HAA and LAA respectively) strains of Hatano rats were originally selected and bred from Sprague-Dawley rats for their performance in the shuttle-box task. The present study focused on the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis of HAA and LAA rats in response to restraint stress. The restraint stress induced an elevation in plasma conc...

Major depression has a high prevalence and a high mortality. In order to understand the molecular changes underlying major depression animal models are needed. The different animal models of depression simulate the etiology and replicates symptoms, course and treatment of human depression properly. In this study, we investigated stress-induced depressogenic induction among the rats using Shuttl...