scholarly journals Indirect exposure to socially defeated conspecifics using recorded video activates the HPA axis and reduces reward sensitivity in mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuko Nakatake ◽  
Hiroki Furuie ◽  
Masatoshi Ukezono ◽  
Misa Yamada ◽  
Kazumi Yoshizawa ◽  
...  

Abstract Rodents perceive the emotional states of conspecifics using vision. In the present study, we demonstrated that exposure to the video-recorded distress of conspecifics induces stress responses in male C57BL/6J mice. A single exposure to a video-recorded scene of the social defeat stress (SDS) increased plasma corticosterone levels in these mice. This physiological change was suppressed by blocking the visual information, suggesting that vision plays a crucial role in inducing stress responses. Furthermore, after exposure to the video, there were increased numbers of c-Fos-positive neurons in the anterior cingulate cortex and other brain areas that are associated with the negative valence and empathy systems, but not in the regions related to the pain signaling. In addition, repeated exposure to SDS videos induced an apparent reduction in reward sensitivity in the sucrose preference test, but did not affect avoidance behaviour in the social interaction test or immobility behaviour in the forced swim test. Reduced reward sensitivity in mice reflects anhedonia, which is a core symptom of depression in humans. Our video SDS model therefore provides a unique opportunity to not only understand the mechanisms underlying stress-induced anhedonia, but also to screen effective candidate molecules for stress-related disorders with greater reproducibility.

Author(s):  
Jessica MacGregor

gene in humans have been shown to predict non-responsiveness to antidepressant drugs; suggesting that FGF2 is required for antidepressants to work. In this study, we hypothesized that antidepressants will not work in rodents that lack the FGF2 gene. Hence, we tested antidepressant treatment in transgenic mice that had the FGF2 gene knocked out. Chronic unpredictable stress (CUS) has been used for several decades to produce a reliable depressive and anxious phenotype in mice. This study followed a CUS paradigm and used fluoxetine (Prozac) as antidepressant treatment. Mice received daily fluoxetine administration beginning on week three of CUS and continued until the end of week five to provide an antidepressant effect and reverse the effects of stress. To test for levels of anxiety and depression, a battery of behavioral tests was conducted which began from the least stressful (i.e. sucrose preference test, open field maze, elevated plus maze) to the most stressful test (forced swim test) to prevent testing carry-over effects. AnyMaze software was used to measure behavior in the open field and elevated plus mazes by recording the amount of time each mouse spent in certain parts of the maze. Future studies will examine brain changes associated with FGF2 gene deletion – particularly in astrocyte cells – which might be necessary for successful antidepressant action. Hopefully, this will elucidate novel therapeutic targets for antidepressant and anti-anxiety medication. 


2017 ◽  
Vol 41 (S1) ◽  
pp. s140-s140 ◽  
Author(s):  
Y. Bansal ◽  
A. Kuhad ◽  
R. Singh ◽  
P. Saroj

Aims and objectivesThe aim of study was to evaluate the pharmacotherapeutic efficacy of NDGA in experimental paradigm of depression i.e. olfactory bulbectomy (OB) specifically targeting kynurenine pathway.Materials and methodDepression like behaviours was induced in OB mice and evaluated by assessment of various behavioural (olfactory deficit test, forced swim test, splash test, open field test, sucrose preference test), biochemical (catalase, reduced glutathione, SOD, nitrite, MAO-A, MDA, corticosterone), inflammatory cytokines (TNF- α, IL-1β, IL-6, IFN-γ) levels and alterations in delta sleep was recorded using EEG. Kynurenine pathway metabolites were determined in plasma and brain using HPLC method. After 14 days post-surgery, olfactory bulbectomized (OBX) mice were administered nordihydroguaiaretic acid (5 mg/kg, 10 mg/kg and 25 mg/kg) daily i.p.ResultsWe have developed a new HPLC method for simultaneous estimation of monoamines and kynurenine pathway metabolites in plasma and brain samples of mice. Chronic treatment with nordihydroguaiaretic acid significantly restored all behavioural, biochemical and neurochemical alterations in OBX mice and increase in quinolinic acid and decrease in kynurenic acid point out the neurodegeneration hypothesis of depression.ConclusionNordihydroguaiaretic acid showed potent neuropharmacotherapeutic effect in OBX mice by virtue of its strong anti-oxidant, anti-inflammatory, anti-stress and by restoring quinolinic acid levels.


2011 ◽  
Vol 115 (4) ◽  
pp. 812-821 ◽  
Author(s):  
Jing Wang ◽  
Yossef Goffer ◽  
Duo Xu ◽  
David S. Tukey ◽  
D. B. Shamir ◽  
...  

Background Chronic pain is associated with depression. In rodents, pain is often assessed by sensory hypersensitivity, which does not sufficiently measure affective responses. Low-dose ketamine has been used to treat both pain and depression, but it is not clear whether ketamine can relieve depression associated with chronic pain and whether this antidepressant effect depends on its antinociceptive properties. Methods The authors examined whether the spared nerve injury model of neuropathic pain induces depressive behavior in rats, using sucrose preference test and forced swim test, and tested whether a subanesthetic dose of ketamine treats spared nerve injury-induced depression. Results Spared nerve injury-treated rats, compared with control rats, showed decreased sucrose preference (0.719 ± 0.068 (mean ± SEM) vs. 0.946 ± 0.010) and enhanced immobility in the forced swim test (107.3 ± 14.6s vs. 56.2 ± 12.5s). Further, sham-operated rats demonstrated depressive behaviors in the acute postoperative period (0.790 ± 0.062 on postoperative day 2). A single subanesthetic dose of ketamine (10 mg/kg) did not alter spared nerve injury-induced hypersensitivity; however, it treated spared nerve injury-associated depression-like behaviors (0.896 ± 0.020 for ketamine vs. 0.663 ± 0.080 for control rats 1 day after administration; 0.858 ± 0.017 for ketamine vs. 0.683 ± 0.077 for control rats 5 days after administration). Conclusions Chronic neuropathic pain leads to depression-like behaviors. The postoperative period also confers vulnerability to depression, possibly due to acute pain. Sucrose preference test and forced swim test may be used to compliment sensory tests for assessment of pain in animal studies. Low-dose ketamine can treat depression-like behaviors induced by chronic neuropathic pain.


2021 ◽  
Vol 22 (15) ◽  
pp. 8195
Author(s):  
Shami Kanekar ◽  
Robert Ettaro ◽  
Michael D. Hoffman ◽  
Hendrik J. Ombach ◽  
Jadeda Brown ◽  
...  

Background: Rates of major depressive disorder (MDD) increase with living at altitude. In our model, rats housed at moderate altitude (in hypobaric hypoxia) exhibit increased depression-like behavior, altered brain serotonin and a lack of antidepressant response to most selective serotonin reuptake inhibitors (SSRIs). A forebrain deficit in the bioenergetic marker creatine is noted in people living at altitude or with MDD. Methods: Rats housed at 4500 ft were given dietary creatine monohydrate (CRMH, 4% w/w, 5 weeks) vs. un-supplemented diet, and impact on depression-like behavior, brain bioenergetics, serotonin and SSRI efficacy assessed. Results: CRMH significantly improved brain creatine in a sex-based manner. At altitude, CRMH increased serotonin levels in the female prefrontal cortex and striatum but reduced male striatal and hippocampal serotonin. Dietary CRMH was antidepressant in the forced swim test and anti-anhedonic in the sucrose preference test in only females at altitude, with motor behavior unchanged. CRMH improved fluoxetine efficacy (20 mg/kg) in only males at altitude: CRMH + SSRI significantly improved male striatal creatine and serotonin vs. CRMH alone. Conclusions: Dietary CRMH exhibits sex-based efficacy in resolving altitude-related deficits in brain biomarkers, depression-like behavior and SSRI efficacy, and may be effective clinically for SSRI-resistant depression at altitude. This is the first study to link CRMH treatment to improving brain serotonin.


Author(s):  
DINESH DHINGRA ◽  
SUDHA

Objectives: The present study was undertaken to investigate the antidepressant potential of trans-anethole in unstressed and stressed male mice. Methods: Swiss albino male mice were exposed to chronic unpredictable mild stress for 21 successive days. Simultaneously, trans-anethole (12.5 mg/kg, 25 mg/kg, and 50 mg/kg) and fluoxetine (20 mg/kg) per se were administered for 21 successive days to separate groups of unstressed and stressed mice. The effect of drugs on depressive-like behavior of mice was tested by tail suspension test (TST) and sucrose preference test. Results: Trans-anethole (25 mg/kg) and fluoxetine significantly decreased the immobility period of unstressed and stressed mice in TST as compared to their respective control. These drugs significantly restored the reduced sucrose preference (%) in stressed mice. Trans-anethole did not show any significant effect on locomotor activity of mice. Antidepressant-like activity of trans-anethole (25 mg/kg) was found to be comparable to fluoxetine. Trans-anethole and fluoxetine significantly inhibited brain monoamine oxidase-A (MAO-A) activity, decreased plasma nitrite, brain malondialdehyde, and increased brain reduced glutathione levels and catalase activity in unstressed and stressed mice. The drugs significantly reversed stress-induced increase in plasma corticosterone levels. Conclusion: Trans-anethole produced significant antidepressant-like activity in unstressed and stressed mice, possibly through inhibition of brain MAO-A activity and alleviation of oxidative stress. Reversal of stress-induced increase in plasma corticosterone levels might also be responsible for antidepressant-like activity of trans-anethole in stressed mice.


2016 ◽  
Vol 29 (4) ◽  
pp. 222-235 ◽  
Author(s):  
Nico Johan Badenhorst ◽  
Linda Brand ◽  
Brian Herbert Harvey ◽  
Susanna Maria Ellis ◽  
Christiaan Beyers Brink

ObjectiveAlthough prescription rates of antidepressants for children and adolescents have increased, concerns have been raised regarding effects on neurodevelopment and long-term outcome. Using a genetic animal model of depression, this study investigated the long-term effects of pre-pubertal administration of fluoxetine (FLX) on depressive-like behaviour in early adulthood, as well as on central monoaminergic response to an acute stressor. We postulated that pre-pubertal FLX will have lasting effects on animal behaviour and monoaminergic stress responses in early adulthood.MethodsFlinders sensitive line (FSL) rats received 10 mg/kg/day FLX subcutaneously from postnatal day 21 (PnD21) to PnD34 (pre-pubertal). Thereafter, following normal housing, rats were either subjected to locomotor testing and the forced swim test (FST) on PnD60 (early adulthood), or underwent surgery for microdialysis, followed on PnD60 by exposure to acute swim stress and measurement of stressor-induced changes in plasma corticosterone and pre-frontal cortical monoamine concentrations.ResultsPre-pubertal FLX did not induce a late emergent effect on immobility in FSL rats on PnD60, whereas locomotor activity was significantly decreased. Acute swim stress on PnD60 significantly increased plasma corticosterone levels, and increased pre-frontal cortical norepinephrine (NE) and 5-hydroxyindole-3-acetic acid (5-HIAA) concentrations. Pre-pubertal FLX significantly blunted the pre-frontal cortical NE and 5-HIAA response following swim stress on PnD60. Baseline dopamine levels were significantly enhanced by pre-pubertal FLX, but no further changes were induced by swim stress.ConclusionPre-pubertal FLX did not have lasting antidepressant-like behavioural effects in genetically susceptible, stress-sensitive FSL rats. However, such treatment reduced locomotor activity, abrogated noradrenergic and serotonergic stressor responses and elevated dopaminergic baseline levels in adulthood.


Science ◽  
2021 ◽  
Vol 371 (6525) ◽  
pp. 153-159 ◽  
Author(s):  
Monique L. Smith ◽  
Naoyuki Asada ◽  
Robert C. Malenka

Empathy is an essential component of social communication that involves experiencing others’ sensory and emotional states. We observed that a brief social interaction with a mouse experiencing pain or morphine analgesia resulted in the transfer of these experiences to its social partner. Optogenetic manipulations demonstrated that the anterior cingulate cortex (ACC) and its projections to the nucleus accumbens (NAc) were selectively involved in the social transfer of both pain and analgesia. By contrast, the ACC→NAc circuit was not necessary for the social transfer of fear, which instead depended on ACC projections to the basolateral amygdala. These findings reveal that the ACC, a brain area strongly implicated in human empathic responses, mediates distinct forms of empathy in mice by influencing different downstream targets.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ning Jiang ◽  
Haixia Wang ◽  
Hong Huang ◽  
Jingwei Lv ◽  
Guirong Zeng ◽  
...  

Depression is a common yet severe neuropsychiatric condition that causes imposes considerable personal, economic, and social burdens worldwide. Medicinal plant species (e.g., Panax ginseng and Polygala tenuifolia) demonstrate potent antidepressant-like effects with less toxicity and other side effects. Shen yuan prescription (SY), composed of Panax ginseng (GT) and Polygala tenuifolia (YT). The present study aimed to elucidate the effects of SY treatment on chronic unpredictable mild stress (CUMS) rats and study the underlying mechanism. Our results indicated that SY (67.5, 135, or 270 mg/kg) significantly reverses the depressive-like behaviors in rats with a 5-week CUMS exposure, as demonstrated by increased sucrose consumption in the sucrose preference test, and decreased immobility time in the tail suspension and forced swim test. Moreover, SY altered serum corticosterone levels, pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α), and oxidative markers (SOD, CAT, and MDA), and increased the levels of hippocampal neurotransmitters (5-HT, DA, and NE) in rats exposed to CUMS. Furthermore, rats treated with SY showed a reduction in the protein expression of BDNF, p-TrkB, p-Akt, and p-mTOR proteins induced by CUMS exposure in the hippocampus. In conclusion, SY prevented depressive-like behaviors in CUMS-exposed rats by preventing hypothalamus-pituitary-adrenal axis dysfunction, decreasing the levels of the neurotransmitters, minimizing oxidative stress, suppressing neuroinflammation, and activating the PI3K/Akt/mTOR-mediated BDNF/TrkB pathway, all of which are the key players in the pathological basis of depression.


2020 ◽  
Vol 47 (4) ◽  
pp. 31-37
Author(s):  
E. Haritov ◽  
J. Tivcheva

AbstractBackground and aims: Increasing evidence indicates that inflammation in the periphery and neuroinflammation in the brain might be involved in the pathophysiology of depressive symptoms in humans. Relatively little is known about the effects of selective serotonin re-uptake inhibitors (SSRI) on individuals exposed to differential dietary regimens, like caloric restriction (CR).The aim of the current study is to assess the antidepressant and antineuroinflammatory effects of CR in single administration and combined with SSRIsantidepressant escitalopram in LPS-induced model of depression in Wistar rats.Materials and methods: For this purpose, we used 36 Wistar rats and applied 3 behavioral tests for depression (FST, SPT and NSFT) in animals and an ELISA-method for measurement of brain IL-1beta levels.Results: Behavioral assessment and results from ELISA-method have shown that CR not only augments the effect of the antidepressant escitalopram on forced swim test (FST) and sucrose preference test (SPT), but also reduces the brain levels of proinflammatory cytokine IL-1beta. Combined with escitalopram, CR enhances antidepressant and antinflamatory properties of this SSRI.Discussion and conclusion: These results show that the response to antidepressive treatment depends on the diverse dietary regimens, especially low-caloric diet. We suggest that the background of this is augmentation of anidepressant and antineuronflammatory properties of some antidepressants by CR. Manipulation of dietary regimens is attractive and new strategy for the management of pharmacoresistant depression.


Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1327
Author(s):  
Seona Patel ◽  
Lindsay Cameron ◽  
David Olson

Social interaction and empathy play critical roles in determining the emotional well-being of humans. Stress-related depression and anxiety can be exacerbated or mitigated depending on specific social conditions. Although rodents are well known to exhibit emotional contagion and consolation behavior, the effects of group housing on stress-induced phenotypes in both males and females are not well established. Here, we investigated how the presence of stressed or unstressed conspecifics within a cage impact depression-related phenotypes. We housed male and female C57BL/6J mice in same-sex groups and subjected them to either gentle handling (GH) or the daily administration of corticosterone (CORT) for 10 days. The GH and CORT treatment groups were divided into cages of unmixed (GH or CORT) and mixed (GH and CORT) treatments. Depression-related phenotypes were measured using the forced swim test (FST) and sucrose preference test (SPT). We found that mixed housing alters FST behavior in a sex-specific manner. Male mice given chronic corticosterone (CORT) that were housed in the same cage as gently handled animals (GH) exhibited increased immobility, whereas GH females housed with CORT females demonstrated the opposite effect. This study underscores the importance of social housing conditions when evaluating stress-induced behavioral phenotypes and suggests that mixed cages of GH and CORT animals yield the greatest difference between treatment groups. The latter finding has important implications for identifying therapeutics capable of rescuing stress-induced behavioral deficits in the FST.


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