Can animals develop depression? An overview and assessment of ‘depression-like’states
Describing certain animal behaviours as ‘depression-like’ or ‘depressive’ has become common across several fields of research. These typically involve unusually low activity or unresponsiveness and/or reduced interest in pleasure (anhedonia). While the term ‘depression-like’ carefully avoids directly claiming that animals are depressed, this narrative review asks whether stronger conclusions can be legitimate, with animals developing […]
Twenty Years of Research on Cytokine-Induced Sickness Behavior
Cytokine-induced sickness behavior was recognized within a few years of the cloning and expression of interferon-α, IL-1 and IL-2, which occurred around the time that the first issue of Brain, Behavior, and Immunity was published in 1987. Phase I clinical trials established that injection of recombinant cytokines into cancer patients led to a variety of […]
Psychoneuroendocrinological links between chronic stress and depression
Objective: The goal of this report is to develop a comprehensive model, which integrates psychosocial and neurobiological aspects, for better understanding the link between chronic stress and mood disorders. Method: A selective review of the relevant bibliography was conducted. The significant data were integrated with clinical and preclinical findings, particularly focusing on the effect of […]
Repeated social defeat stress induces chronic hyperthermia in rats
Psychological stressors are known to increase core body temperature (Tc) in laboratory animals. Such single stress-induced hyperthermic responses are typically monophasic, as Tc returns to baseline within several hours. However, studies on the effects of repeated psychological stress on Tc are limited. Therefore, we measured Tc changes in male Wistar rats after they were subjected […]
Novelty-seeking behavior predicts vulnerability in a rodent model of depression
Background The onset of major depressive disorder is likely precipitated by a combination of heredity and life stress. The present study tested the hypothesis that rats selectively bred on a trait related to emotional reactivity would show differential susceptibility or resilience to the development of depression-like signs in response to chronic mild variable intermittent stress […]
Effects of chronic stress: A comparison between tethered and loose sows
The present study aimed to investigate whether long-lasting, recurrent tethering of sows leads to enduring effects on measures that may be indicative of chronic stress. Sows that had experienced tethering for about 1.5 or 4.5 years and age-matched sows kept in a social housing system (loose sows) were compared. Immediately after slaughter, blood samples were taken […]
Lambs prevented from suckling their mothers display behavioral, immune and endocrine disturbances
The aim of the experiment was to assess the effects of either maternal deprivation or prevented suckling on lambs. Thirty Comisana lambs were assigned to a control dam-suckled group (DS) and two test groups of 10 each. Test lambs were maintained with their mothers 24 to 30 h after parturition and subsequently offered ewe milk […]
Sex differences in the effects of two stress paradigms on dopaminergic neurotransmission
Sex differences in behavioral and neurobiological responses to stress are considered to modulate the prevalence of some psychiatric disorders, including major depression. In the present study, we compared dopaminergic neurotransmission and behavior in response to two different stress paradigms, the Forced Swim Test (FST) and the Chronic Mild Stress (CMS). Male and female rats were […]
Signs of attenuated depression-like behavior in vasopressin deficient Brattleboro rats
Vasopressin, a peptide hormone functioning also as a neurotransmitter, neuromodulator and regulator of the stress response is considered to be one of the factors related to the development and course of depression. In the present study, we have tested the hypothesis that congenital deficit of vasopressin in Brattleboro rats leads to attenuated depression-like behavior in […]
Measuring emotional processes in animals: the utility of a cognitive approach
Contemporary researchers regard emotional states as multifaceted, comprising physiological, behavioural, cognitive and subjective components. Subjective, conscious experience of emotion can be inferred from linguistic report in humans, but is inaccessible to direct measurement in non-human animals. However, measurement of other components of emotion is possible, and a variety of methods exist for monitoring emotional processes […]