Pathological changes in the spleen of mice subjected to different time courses of restraint stress.
Scientific reports
The objective of this study was to investigate spleen pathology and immune cell subset alterations in mice exposed to acute and chronic restraint stress over various timeframes. A deeper understanding of stress-induced spleen injuries can provide new insights into the mechanisms underlying stress-induced disorders. C57BL/6N mice were restrained for different durations (1, 3, 7, 14 and 21 days) for 6-8 h daily. The control mice were observed at the same time points. Post restraint, behavioural experiments were conducted to assess spleen weight, gross morphology and microscopic histological changes. Immunohistochemical staining was used to detect changes in glucocorticoid receptor (GR) expression, immune cell subsets and cell proliferation in response to stress. Our analysis revealed significant behavioural abnormalities in the stressed mice. In particular, there was an increase in the nuclear expression of GR beginning on Day 3, and it peaked on Day 14. The spleens of stressed mice displayed a reduction in size, disordered internal tissue structure and reduced cell proliferation. NK cells and M2-type macrophages exhibited immune cell subset alterations under stress, whereas T or B cells remained unaltered. Restraint stress can lead to pathomorphological alterations in spleen morphology, cell proliferation and immune cell counts in mice. These findings suggest that stress-induced pathological changes can disrupt immune regulation during stress.
10.1038/s41598-024-64475-w
Chronic restraint stress modulates expression of genes in murine spleen.
Yin Deling,Zhang Ying,Stuart Charles,Miao Junying,Zhang Yi,Li Chuanfu,Zeng Xiao,Hanley Gregory,Moorman Jonathan,Yao Zhiqiang,Woodruff Michael
Journal of neuroimmunology
Psychological and physical stress can alter the immune system in both humans and animals. We have reported that mice subjected to chronic 12-h daily physical restraint for 2 days showed dramatic apoptosis in splenocytes. To identify genes that contribute to the splenocyte apoptosis, we compare gene expression in the spleens of restrained and unstressed mice using oligo microarrays consisting of 226 genes. We report here that mice subjected to chronic 12-h daily physical restraint for 2 days exhibited significantly altered expression of 50 of 226 genes. These genes included pro-apoptotic genes. We selected 5 genes of interest and confirmed the microarray results by real-time PCR. In this study, we identify a potentially important component of pro-apoptotic activity in restraint stress and suggest a possible target for anti-apoptotic therapy to protect splenocytes against stress-induced apoptosis.
10.1016/j.jneuroim.2006.05.004
17beta-estradiol attenuates hippocampal neuronal loss and cognitive dysfunction induced by chronic restraint stress in ovariectomized rats.
Takuma K,Matsuo A,Himeno Y,Hoshina Y,Ohno Y,Funatsu Y,Arai S,Kamei H,Mizoguchi H,Nagai T,Koike K,Inoue M,Yamada K
Neuroscience
Several lines of evidence suggest that hormonal changes after menopause may play an important role in the incidence of cognitive dysfunction, and also in the development of Alzheimer's disease. In this study, we investigated the effect of estrogen on cognitive function in rats under different stress environment. Female rats were divided into four groups: two groups were ovariectomized (OVX) and two were sham-operated. One group each of OVX and sham rats was kept in a normal environment, and the other groups were assigned to a daily restraint stress (6 h/day) for 21 days from 2 months after the operation. Following the stress period, subjects were tested for performance in novel object recognition test and then used for morphological and neurochemical analyses. The OVX plus stress (OVX/stress) group showed a significant impairment of recognition of novel objects, compared with the other groups. The OVX/stress group also showed a marked decrease in the number of pyramidal cells of the CA3 region and levels of brain-derived neurotrophic factor mRNA in the hippocampus. We further examined the effect of estrogen against cognitive dysfunction and hippocampal changes of OVX/stress rats. Vehicle or 17beta-estradiol (E2) at 20 microg/day was s.c. administered to OVX/stress rats from 2 days before the stress period to the end of behavioral analysis through an implantable osmotic pump. Chronic E2 treatment decreased stress response and improved the cognitive and morphological impairments relative to vehicle group. These data have important implications for cognition enhancing effect of estrogen treatment in postmenopausal women.
10.1016/j.neuroscience.2007.01.017
The co-expression of GluN2B subunits of the NMDA receptors and glucocorticoid receptors after chronic restraint stress in low and high anxiety rats.
Lehner Małgorzata,Wisłowska-Stanek Aleksandra,Gryz Marek,Sobolewska Alicja,Turzyńska Danuta,Chmielewska Natalia,Krząścik Paweł,Skórzewska Anna,Płaźnik Adam
Behavioural brain research
The aim of this study was to assess the mechanisms underlying behavioural differences between high- (HR) and low- (LR) anxiety rats, selected according to their behaviour in the contextual fear test (i.e., the duration of the freezing response was used as a discriminating variable), after a chronic restraint procedure (21days, 3h daily). We analysed the expression of the GluN2B subunits of the NMDA and glucocorticoid receptors (GRs) in selected brain structures (immunofluorescence). Following chronic restraint stress in the HR rats, we observed a decrease in the expression of the GRs and GluN2B subunits of the NMDA receptor in the prefrontal cortical areas and the hippocampus compared to the HR-control and the LR-restraint groups. These effects coincided with an increase in passive depressive-like behaviour in the Porsolt test of the HR rats. Moreover, in the hippocampus, the HR-restraint animals demonstrated decreased glutamate levels and a decreased glutamate/glutamine ratio compared to the LR-restraint rats. Furthermore, the HR-restraint group had increased GRs/GluN2B subunits colocalisation in the basolateral amygdala (BLA) compared to the HR-control and the LR-restraint rats. The present results suggest that in HR rats exposed to chronic restraint stress, the hippocampal and cortical glutamatergic system components are changed. These effects could have a negative influence on the feedback mechanisms regulating the hypothalamic-pituitary-adrenal axis as well as on the behavioural processes expressed as depressive-like symptoms.
10.1016/j.bbr.2016.11.004
Effect of chronic stress and L-carnitine on rat stomach.
Izgüt-Uysal V Nimet,Bülbül Mehmet,Tan Ruken,Derin Narin,Ustünel Ismail,Ağar Aysel,Yargiçoğlu Piraye
The journal of physiological sciences : JPS
BACKGROUND AND AIM:L-Carnitine is an essential cofactor in the mitochondrial transfer of fatty acids, and it is also a scavenger of free radicals in mammalian tissues. The aim of the study was to determine the effect of L-carnitine on chronic restraint stress-induced gastric mucosal injury. METHODS:Wistar rats were applied restraint stress (1 h/day) and L-carnitine (50 mg/kg) for 21 days. The lesion index, prostaglandin E(2) and mucus content, lipid peroxidation, superoxide dismutase, and catalase activity in gastric mucosa were evaluated. RESULTS:Chronic restraint stress increased the lesion index, lipid peroxidation, and superoxide dismutase activity in gastric mucosa, and it decreased prostaglandin E(2) and mucus content. L-Carnitine treatment prevented the stress-induced increase in lesion index, lipid peroxidation and a stress-induced decline in prostaglandin E(2), and mucus content in gastric mucosa, but it increased catalase activity. CONCLUSIONS:L-Carnitine prevents the occurrence of lesion by strengthening the gastric mucosal barrier and by reducing lipid peroxidation against the harmful effects of chronic restraint stress.
10.2170/physiolsci.RP004707
Effect of chronic intermittent restraint stress on hippocampal expression of marker proteins for synaptic plasticity and progenitor cell proliferation in rats.
Rosenbrock Holger,Koros Eliza,Bloching Anita,Podhorna Jana,Borsini Franco
Brain research
Chronic restraint stress may change hippocampal mRNA levels of markers for synaptic plasticity such as synaptophysin, growth-associated protein 43 (GAP-43), and brain-derived neurotrophic factor (BDNF). In order to examine the relation between that stressor and those biochemical markers on protein level as well as the Ki-67 protein, a marker of progenitor cell proliferation, we subjected rats to chronic intermittent restraint stress for 6 h per day for 14 days excluding the weekends. This stress intensity caused a significant increase in adrenal gland weight and decrease in body weight gain. However, we did not find significant alteration of protein expression levels for synaptophysin, GAP-43, and BDNF by using Western blot analysis. Unlike these findings, the hippocampal protein expression of Ki-67 was significantly reduced by using both Western blot and immunohistochemical analyses. This reduction of Ki-67 expression in chronically stressed rats was correlated with increased adrenal gland weight and decreased body weight gain. All marker proteins used did not show any changes of hippocampal expression level after a single restraint stress session of 3 h. In conclusion, chronic intermittent restraint stress caused changes in the physiological stress response in rats, and a decrease of hippocampal progenitor cells using the Ki-67 protein as marker which indicates a suppression of adult neurogenesis. The results might contribute to understand the relationship between stress and cellular neurobiology of depression, since chronic antidepressant treatment have been shown to increase adult neurogenesis in the rat hippocampus.
10.1016/j.brainres.2005.01.065
Structural and functional alterations to rat medial prefrontal cortex following chronic restraint stress and recovery.
Neuroscience
Chronic stress has been shown in animal models to result in altered dendritic morphology of pyramidal neurons of the medial prefrontal cortex (mPFC). It has been hypothesized that the stress-induced dendritic retractions and spine loss lead to disrupted connectivity that results in stress-induced functional impairment of mPFC. While these alterations were initially viewed as a neurodegenerative event, it has recently been established that stress induced dendritic alterations are reversible if animals are given time to recover from chronic stress. However, whether spine growth accompanies dendritic extension remains to be demonstrated. It is also not known if recovery-phase dendritic extension allows for re-establishment of functional capacity. The goal of this study, therefore, was to characterize the structural and functional effects of chronic stress and recovery on the infralimbic (IL) region of the rat mPFC. We compared neuronal morphology of IL layer V pyramidal neurons from male Sprague-Dawley rats subjected to 21 days of chronic restraint stress (CRS) to those that experienced CRS followed by a 21 day recovery period. Layer V pyramidal cell functional capacity was assessed by intra-IL long-term potentiation (LTP) both in the absence and presence of SKF38393, a dopamine receptor partial agonist and a known PFC LTP modulator. We found that stress-induced IL apical dendritic retraction and spine loss co-occur with receptor-mediated impairments to catecholaminergic facilitation of synaptic plasticity. We also found that while post-stress recovery did not reverse distal dendritic retraction, it did result in over extension of proximal dendritic arbors and spine growth as well as a full reversal of CRS-induced impairments to catecholaminergic-mediated synaptic plasticity. Our results support the hypothesis that disease-related PFC dysfunction is a consequence of network disruption secondary to altered structural and functional plasticity and that circuitry reestablishment may underlie elements of recovery. Accordingly, we believe that pharmacological treatments targeted at preventing dendritic retraction and spine loss or encouraging circuitry re-establishment and stabilization may be advantageous in the prevention and treatment of mood and anxiety disorders.
10.1016/j.neuroscience.2009.08.053
The effects of chronic stress on hippocampal morphology and function: an evaluation of chronic restraint paradigms.
McLaughlin Katie J,Gomez Juan L,Baran Sarah E,Conrad Cheryl D
Brain research
Chronic restraint stress for 6 h/21 days causes hippocampal CA3 apical dendritic retraction, which parallels spatial memory impairments in male rats. Recent research suggests that chronic immobilization stress for 2 h/10 days induces CA3 dendritic retraction [Vyas, A., Mitra, R., Shankaranarayana Rao, B.S., Chattarji, S., 2002. Chronic stress induces contrasting patterns of dendritic remodeling in hippocampal and amygdaloid neurons. J. Neurosci. 22, 6810-6818.] and questions whether CA3 dendritic retraction and spatial memory deficits can be produced sooner than found following 6 h/21 days of restraint stress. Therefore, this study investigated the effects of four different durations of chronic restraint stress (varied by hours/day and total number of days) and the subsequent effects on hippocampal CA3 morphology and spatial memory in the same male Sprague-Dawley rats. The results showed that only rats exposed to the 6 h/21 days restraint paradigm exhibited CA3 apical dendritic retraction, consistent spatial memory deficits, and decreased body weight gain compared to experimental counterparts and controls. While chronically stressing a rat with wire mesh restraint has a physical component, it acts primarily as a psychological stressor, and these findings support the interpretation that chronic psychological stress produces hippocampal-dependent cognitive deficits that are consistent with hippocampal structural changes. Differences in stress effects observed across different studies may be due to rat strain, type of stressor, and housing conditions; however, the current findings support the use of chronic restraint stress, with wire mesh, for 6 h/21 days as a reliable and efficient method to produce psychological stress and to cause CA3 dendritic retraction and spatial memory deficits in male Sprague-Dawley rats.
10.1016/j.brainres.2007.05.042
Increased density and synapto-protective effect of adenosine A2A receptors upon sub-chronic restraint stress.
Cunha G M A,Canas P M,Oliveira C R,Cunha R A
Neuroscience
Stress initially causes adaptive changes in the brain and can lead to neurodegeneration if continuously present. Noxious brain conditions trigger the release of adenosine that can control brain function and neurodegeneration through inhibitory A(1) and facilitatory A(2A) receptors. We tested the effect of restraint stress on the density of adenosine receptors and their effect on the outcome of stress, focusing in a known affected region, the hippocampus. Sub-chronic restraint stress (6 h/day for 7 days) caused a parallel decrease of the density of A(1) receptors (15-20%) and an increase (near 250%) of A(2A) receptor density in rat hippocampal nerve terminals. This indicates that sub-chronic stress unbalances adenosine receptors, up-regulating A(2A) and down-regulating A(1) receptors. Sub-chronic stress did not cause hippocampal neurodegeneration but decreased the immunoreactivity (immunohistochemistry and Western blot) of a synaptic marker, synaptophysin. The blockade of A(2A) receptors with 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine (0.05 mg/kg, daily i.p. injection) attenuated the loss of synaptophysin immunoreactivity observed in the hippocampus of rats subjected to sub-chronic restraint stress. This ability of A(2A) receptor antagonists to prevent the earliest stress-induced synaptic modifications provides a neurochemical and morphological correlate for the interest of A(2A) receptor antagonists to attenuate the burden of chronic stress.
10.1016/j.neuroscience.2006.05.024
Interactive effects of chronic stress and a high-sucrose diet on nonalcoholic fatty liver in young adult male rats.
Corona-Pérez Adriana,Díaz-Muñoz Mauricio,Cuevas-Romero Estela,Luna-Moreno Dalia,Valente-Godínez Héctor,Vázquez-Martínez Olivia,Martínez-Gómez Margarita,Rodríguez-Antolín Jorge,Nicolás-Toledo Leticia
Stress (Amsterdam, Netherlands)
Glucocorticoids have been implicated in nonalcoholic fatty liver diseases (NAFLD). The influence of a palatable diet on the response to stress is controversial. This study explored whether a high-sucrose diet could protect from hepatic steatosis induced by chronic restraint stress in young adult rats. Male Wistar rats aged 21 days were allocated into four groups (n = 6-8 per group): control, chronic restraint stress, 30% sucrose diet, and 30% sucrose diet plus chronic restraint stress. After being exposed to either tap water or sucrose solution during eight weeks, half of the rats belonging to each group were subject or not to repeated restraint stress (1 h per day, 5 days per week) during four weeks. Triacylglycerol (TAG), oxidative stress, activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1), infiltration of immune cells, and glycogen amount in the liver were quantified. Serum concentrations of corticosterone and testosterone were also measured. The stressed group showed normal serum concentrations of corticosterone and did not have hepatic steatosis. However, this group showed increased glycogen, inflammation, mild fibrosis, oxidative stress, and a high activity of 11β-HSD-1 in the liver. The group exposed to the high-sucrose diet had lower concentrations of corticosterone, hepatic steatosis and moderate fibrosis. The group subject to high-sucrose diet plus chronic restraint stress showed low concentrations of corticosterone, hepatic steatosis, oxidative stress, and high concentrations of testosterone. Thus, restraint stress and a high-sucrose diet each generate different components of nonalcoholic fatty liver in young adult rats. The combination of both the factors could promote a faster development of NAFLD.
10.1080/10253890.2017.1381840
Multi-omics analysis of pathological changes in the amygdala of rats subjected to chronic restraint stress.
Li Zhonghua,Gao Chong,Peng Jin,Liu Min,Cong Bin
Behavioural brain research
OBJECTIVE:Overwhelming stress potentially results in the occurrence of many mental diseases. The amygdala is one region in the brain targeted by stress. Recent studies have shown that changes in the amygdala of subjects under stress are related to depression, anxiety and post-traumatic stress disorder (PTSD). However, researchers have not clearly elucidated the changes in the amygdala in response to stress and the underlying mechanism. We conducted several experiments to understand this mechanism. METHODS:In this study, we first established a rat model of chronic restraint stress (CRS) and observed the changes in behavior and neurons in the amygdala. Second, an integrated metabolomics and proteomics experiment was conducted to identify potential stress-related biomarkers. Finally, we validated two molecules of interest and detected four apoptosis-related proteins using Western blotting to further determine the related mechanisms. RESULTS:Our study revealed the presence of anxiety-like behaviors and pathological changes in amygdalar neurons in the rat model. In the multi-omics analysis, 19 potential molecules were identified. Western blotting confirmed consistent changes in the levels of Cry1 and Brcc36 obtained in previous results. The levels of proteins in the ataxia telangiectasia mutated (ATM) pathway were increased in the CRS group. CONCLUSIONS:CRS causes anxiety-like behaviors that are potentially related to decreased levels of GABA in the amygdala. Moreover, CRS potentially alters the levels of Cry1 and Brcc36 and results in circadian rhythm disorder and impairments in DNA repair and apoptosis in the amygdala through a mechanism mediated by the ATM pathway.
10.1016/j.bbr.2020.112735
Effects of chronic stress on rat heart function following regional ischemia: a sex-dependent investigation.
American journal of physiology. Heart and circulatory physiology
Chronic psychological stress is a recognized, yet understudied risk factor for heart disease, with potential sex-specific effects. We investigated whether chronic stress triggers sex-dependent cardiac dysfunction in isolated Wistar rat hearts subjected to ischemia-reperfusion injury. The experimental cohort underwent 1 h of daily restraint stress for 4 wk versus matched controls, followed by euthanasia (sodium pentobarbital) and heart excision for ex vivo perfusion. Blood analysis revealed sex-specific alterations in stress hormones and inflammatory markers. When compared with controls, chronic restraint stress (CRS) males displayed decreased plasma brain-derived neurotrophic factor (BDNF) levels ( < 0.05), whereas CRS females exhibited elevated plasma adrenocorticotropic hormone (ACTH) ( < 0.01) and reduced corticosterone ( < 0.001) alongside lower serum estradiol ( < 0.001) and estradiol/progesterone ratio ( < 0.01). Of note, CRS females showed increased serum cardiac troponin T ( < 0.05) and tumor necrosis factor-α (TNF-α) ( < 0.01) with suppressed interleukin (IL)-1α, IL-1β, IL-6, and IL-10 levels ( < 0.05) when compared with controls. Ex vivo Langendorff perfusions revealed that CRS female hearts displayed impaired postischemic functional recovery for baseline stroke volume (SV, < 0.01), work performance ( < 0.05), aortic output (AO, < 0.05), coronary flow (CF, < 0.01), and overall cardiac output (CO, < 0.01) when compared with matched controls and CRS males ( < 0.05). Our findings reveal intriguing sex-specific responses at both the systemic and functional levels in stressed hearts. Here, the dysregulation of stress hormones, proinflammatory state, and potential underlying cardiomyopathy in females following the stress protocol renders them more prone to damage following myocardial ischemia. This study emphasizes the importance of incorporating sex as a biological variable in cardiac research focusing on stress-related cardiomyopathy. Although chronic psychological stress is a risk factor for cardiovascular diseases, the underlying mechanisms remain poorly understood. This study revealed that chronic restraint stress resulted in systemic changes (dysregulated stress hormones, proinflammatory state) and potential cardiomyopathy in females versus controls and their male counterparts. The stressed female hearts also displayed reduced functional recovery following ex vivo ischemia-reperfusion. This highlights the importance of incorporating sex as a biological variable in cardiac research.
10.1152/ajpheart.00424.2024
Protective effect of grape seed extract against chronic physical stress-induced zona fasciculata injury in male rats: Functional, immunohistochemical and electron microscopic study.
Microscopy research and technique
In the present study, we investigated the antioxidant effect of grape seed extract (GSE) against chronic immobilization stress-induced zona fasciculata injury in Wistar male rats. Thirty male rats were divided into three groups: Non-stress group: rats were not subjected to stress protocol and received distilled water orally for 30 days. Stress group: rats received distilled water orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), distilled water was continued along with the constant stress experiment. GSE-stress group: rats treated with oral GSE (300 mg/kg), administered orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), GSE was continued along with the stress exposure. Chronic stress was induced by placing each animal in a restrainer for 2 h daily for 15 consecutive days in both Stress and GSE-stress groups. The serum corticosterone and adrenal cortex malondialdehyde (MDA) levels were measured as indices of stress. Immunohistochemistry of the inducible nitric oxide synthase (iNOS) as a nitrosative stress marker beside the adrenal cortex's ultrastructure, particularly zona fasciculata, was assessed. Chronic restraint stress significantly elevated the serum corticosterone and adrenal cortex MDA levels, while oral administration of GSE reduced the serum corticosterone level, adrenal cortex MDA levels, and iNOS immunoreactivity in zona fasciculata. Besides, adrenocortical ultrastructure significantly improved. These results suggested that GSE enhanced the antioxidant defense against reactive oxygen species produced under chronic stress conditions, protecting the adrenal cortex. RESEARCH HIGHLIGHTS: This research highlighted the significant protective effects of grape seed extract administration on the histological findings, both in light and electron microscopic studies, as well as the biochemical and functional parameters in cases of stress-induced adrenal cortex injury in rats.
10.1002/jemt.24130
Changes in the brain expression of alpha-2 subunits of the GABA-A receptor after chronic restraint stress in low- and high-anxiety rats.
Wisłowska-Stanek Aleksandra,Lehner Małgorzata,Skórzewska Anna,Krząścik Paweł,Maciejak Piotr,Szyndler Janusz,Ziemba Andrzej,Płaźnik Adam
Behavioural brain research
This study assessed the mechanisms underlying the behavioral differences between high- (HR) and low-anxiety (LR) rats selected for their behavior in the contextual fear test (i.e., the duration of the freezing response was used as a discriminating variable). Rats were subjected to chronic restraint stress (21 days, 3h daily). We found that in the HR group, chronic restraint stress decreased rat activity in the Porsolt test and reduced the concentration of corticosterone in the prefrontal cortex. The behavioral changes were accompanied by a lower expression of alpha-2 GABA-A receptor subunits in the secondary motor cortex (M2 area) and in the dentate gyrus of the hippocampus (DG) compared to LR restraint animals. Moreover, restraint stress increased the density of alpha-2 GABA-A subunits in the basolateral amygdala (BLA) in HR rats and decreased the expression of these subunits in the DG and M2 areas compared to the HR control group. The present results suggest that, in HR rats exposed to chronic restraint stress, the function of hippocampal and cortical GABAergic neurotransmission is attenuated and that this effect could have important influences on the functioning of the hypothalamic-pituitary-adrenal axis and on depressive symptoms.
10.1016/j.bbr.2013.07.042
Chronic restraint stress promotes learning and memory impairment due to enhanced neuronal endoplasmic reticulum stress in the frontal cortex and hippocampus in male mice.
Huang Rong-Rong,Hu Wen,Yin Yan-Yan,Wang Yu-Chan,Li Wei-Ping,Li Wei-Zu
International journal of molecular medicine
Chronic stress has been implicated in many types of neurodegenerative diseases, such as Alzheimer's disease (AD). In our previous study, we demonstrated that chronic restraint stress (CRS) induced reactive oxygen species (ROS) overproduction and oxidative damage in the frontal cortex and hippocampus in mice. In the present study, we investigated the effects of CRS (over a period of 8 weeks) on learning and memory impairment and endoplasmic reticulum (ER) stress in the frontal cortex and hippocampus in male mice. The Morris water maze was used to investigate the effects of CRS on learning and memory impairment. Immunohistochemistry and immunoblot analysis were also used to determine the expression levels of protein kinase C α (PKCα), 78 kDa glucose-regulated protein (GRP78), C/EBP-homologous protein (CHOP) and mesencephalic astrocyte-derived neurotrophic factor (MANF). The results revealed that CRS significantly accelerated learning and memory impairment, and induced neuronal damage in the frontal cortex and hippocampus CA1 region. Moreover, CRS significantly increased the expression of PKCα, CHOP and MANF, and decreased that of GRP78 in the frontal cortex and hippocampus. Our data suggest that exposure to CRS (for 8 weeks) significantly accelerates learning and memory impairment, and the mechanisms involved may be related to ER stress in the frontal cortex and hippocampus.
10.3892/ijmm.2014.2026
Comparing the Effects of Chlorogenic Acid and Ilex paraguariensis Extracts on Different Markers of Brain Alterations in Rats Subjected to Chronic Restraint Stress.
de Lima María Eduarda,Ceolin Colpo Ana Z,Maya-López Marisol,Rangel-López Edgar,Becerril-Chávez Hugo,Galván-Arzate Sonia,Villeda-Hernández Juana,Sánchez-Chapul Laura,Túnez Isaac,Folmer Vanderlei,Santamaría Abel
Neurotoxicity research
Positive influence of yerba mate (Ilex paraguariensis) on human health issues has been attributed to its frequent consumption in South American countries and is assumed to be due to its high content of antioxidant compounds, including chlorogenic acid (CGA); however, hard evidence about its positive effects under chronic stress conditions is still required. In this study, the effects of yerba mate extracts (IpE), and its main compound chlorogenic acid (CGA), on behavioral and morphological endpoints of brain damage induced by chronic restraint stress (CRS) to rats were evaluated and compared. CRS sessions were performed during 21 days. IpE (200 mg/mL, p.o.) or CGA (2 mg/mL, p.o.) were administered daily 30 min before stress. Behavioral tests comprised motor skills and anxiety-like activity. Histological (H&E) and histochemical changes were explored in three brain regions: cortex (Cx), hippocampus (Hp), and striatum (S). Rats subjected to CRS exhibited hypoactive patterns of locomotor activity. Rats receiving IpE before CRS preserved the basal locomotor activity. Stressed animals also augmented the anxiety-like activity, whereas IpE normalized exploratory behavior. Stressed animals presented cell damage in all regions. Morphological damage was more effectively prevented by IpE than CGA. Stressed animals also augmented the expression/localization pattern of the tumor necrosis factor alpha in the striatum and the expression of the glial fibrillary acidic protein in the hippocampus (stratum moleculare) and cortex, whereas IpE and CGA reduced the expression of these molecules. In turn, CGA exhibited only moderate protective effects on all markers analyzed. Our findings support a protective role of IpE against CRS, which may be related to the antioxidant and anti-inflammatory properties of its compounds. Since CGA was unable to prevent all the alterations induced by CRS, it is concluded that the protective properties of the whole extract of Ilex paraguariensis are the result of the combined effects of all its natural antioxidant compounds, and not only of the properties of CGA.
10.1007/s12640-018-9963-6
Chronic social defeat, but not restraint stress, alters bladder function in mice.
Mann Elizabeth A,Alam Zaheer,Hufgard Jillian R,Mogle Melissa,Williams Michael T,Vorhees Charles V,Reddy Pramod
Physiology & behavior
BACKGROUND:Voiding disorders in humans, particularly in children are associated with increased incidence of behavioral issues as well as past history of childhood abuse. We hypothesized that creating stress in mice, utilizing either a chronic social defeat model (SD) or restraint stress in shallow water model (RSSW) would engender changes in bladder function, morphology, and behavior, thereby enabling us to study the resultant voiding dysfunction. METHODS:For SD stress (14 days), C57BL/6 male mice were exposed daily to a larger aggressive CD-1 male for 10 min, followed by sensory exposure in a barrier cage for 24h. Control mice were similarly housed with no exposure. For RSSW (21 days), C57BL/6 mice were put in a perforated conical tube with feet immersed in water daily for 4h, then returned to single housing cages. Control mice were also in single housing. After the stress period, voiding patterns were obtained on filter paper, followed by behavioral tests. At necropsy, blood was taken for corticosterone analysis, and bladder and body weights measured. Bladder cryosections were stained with hematoxylin and eosin (H&E) for morphological assessment. Sequential sections were immunostained with antibodies to Ki-67 as a proliferation marker, CD31 (endothelial cell marker), and uroplakin-II. ImageJ software was used to measure bladder wall thickness on blinded H&E photomicrographs as well as quantitate CD31 staining. Both Ki-67-positive and -negative nuclei were counted with Imaris software to obtain a proliferation index. RESULTS:Only SD mice had a single large void pattern. Bladder-to-body weight ratios increased in SD mice (p≤0.02) but not in RSSW mice. Plasma corticosterone levels were elevated in all stressed mice. SD mice exhibited lower levels of locomotor activity compared with controls; RSSW mice were hyperactive. In SD mice, bladder wall thickness was increased (p ≤ 0.003) but no change was seen in Ki-67 proliferation index, consistent with hypertrophy. No difference with control mice was seen in vascularity as visualized by CD31 staining. Uniform uroplakin-II staining lined the urothelium of both SD and control mice. CONCLUSIONS:Mice exposed to repeated SD (14 days) respond with altered voiding indicative of urine retention, and exhibit bladder wall changes consistent with hypertrophy while the urothelial barrier is maintained. These changes were not observed with repeated RSSW. SD, in contrast to RSSW, provides a model of psychological stress to further study the interplay of behavior and bladder dysfunction, enabling an improved understanding of voiding dysfunction, and the ability to create innovative and more effective management pathways for children who present with voiding dysfunction.
10.1016/j.physbeh.2015.02.021
Erythropoietin prevents the effect of chronic restraint stress on the number of hippocampal CA3c dendritic terminals-relation to expression of genes involved in synaptic plasticity, angiogenesis, inflammation, and oxidative stress in male rats.
Aalling Nadia,Hageman Ida,Miskowiak Kamilla,Orlowski Dariusz,Wegener Gregers,Wortwein Gitta
Journal of neuroscience research
Stress-induced allostatic load affects a variety of biological processes including synaptic plasticity, angiogenesis, oxidative stress, and inflammation in the brain, especially in the hippocampus. Erythropoietin (EPO) is a pleiotropic cytokine that has shown promising neuroprotective effects. Recombinant human EPO is currently highlighted as a new candidate treatment for cognitive impairment in neuropsychiatric disorders. Because EPO enhances synaptic plasticity, attenuates oxidative stress, and inhibits generation of proinflammatory cytokines, EPO may be able to modulate the effects of stress-induced allostatic load at the molecular level. The aim of this study was therefore to investigate how EPO and repeated restraint stress, separately and combined, influence (i) behavior in the novelty-suppressed feeding test of depression/anxiety-related behavior; (ii) mRNA levels of genes encoding proteins involved in synaptic plasticity, angiogenesis, oxidative stress, and inflammation; and (iii) remodeling of the dendritic structure of the CA3c area of the hippocampus in male rats. As expected, chronic restraint stress lowered the number of CA3c apical dendritic terminals, and EPO treatment reversed this effect. Interestingly, these effects seemed to be mechanistically distinct, as stress and EPO had differential effects on gene expression. While chronic restraint stress lowered the expression of spinophilin, tumor necrosis factor α, and heat shock protein 72, EPO increased expression of hypoxia-inducible factor-2α and lowered the expression of vascular endothelial growth factor in hippocampus. These findings indicate that the effects of treatment with EPO follow different molecular pathways and do not directly counteract the effects of stress in the hippocampus.
10.1002/jnr.24107
Effects of Chronic Stress and Comfort Food in Testicular Morphology in Adult Wistar Rats.
International braz j urol : official journal of the Brazilian Society of Urology
PURPOSE:To investigate the effect of chronic stress on testicular morphology in adult Wistar rats, as well as the impact of comfort food consumption on these parameters. MATERIAL AND METHODS:32 Wistar rats (10 weeks old) were divided into four groups: control (C), stressed (S), control + comfort food (C+CF), and stressed + comfort food (S+CF). Chronic stress was induced by the restraint method during 8 weeks in groups S and S+CF, while groups C and C+CF were maintained under normal conditions. Groups C and S received a standard rat chow diet, while groups C+CF and S+CF received both the standard chow and comfort food (Froot Loops®). After 8 weeks of experiment, all animals were euthanized and the testes were collected for histomorphometric, immunohistochemical and gene expression analysis. RESULTS:Comfort food was preferred over standard chow in groups C+CF and S+CF, but this preference was more preeminent in stressed animals (S+CF). The consumption of comfort food resulted in testicular weight reduction. The seminipherous epithelium was reduced in group S in comparison to controls. While comfort food also reduced the epithelium in C+CF in comparison to controls, for group S+CF the comfort food ameliorated the stress-induced damage. The cell proliferation rate and the relative expression of StAR and BLC2 genes were similar between the groups. CONCLUSION:Both chronic stress and comfort food consumption resulted in morphological alterations of the testes but the consumption of comfort foods during chronic stress partially prevented the stress-induced detrimental effects on testes.
10.1590/S1677-5538.IBJU.2024.0515
Chronic restraint stress induces intestinal inflammation and alters the expression of hexose and lipid transporters.
Lee Chooi Yeng
Clinical and experimental pharmacology & physiology
Psychosocial stress is reported to be one of the main causes of obesity. Based on observations in studies that relate stress and gut inflammation to obesity, the present study hypothesized that chronic stress, via inflammation, alters the expression of nutrient transporters and contributes to the development of metabolic syndrome. Rats were exposed to restraint stress for 4 h/day for 5 days/week for eight consecutive weeks. Different segments of rat intestine were then collected and analysed for signs of pathophysiological changes and the expression of Niemann-Pick C1-like-1 (NPC1L1), sodium-dependent glucose transporter-1 (SLC5A1, previously known as SGLT1) and facilitative glucose transporter-2 (SLC2A2, previously known as GLUT2). In a separate experiment, the total anti-oxidant activity (TAA)-time profile of control isolated intestinal segments was measured. Stress decreased the expression of NPC1L1 in the ileum and upregulated SLC5A1 in both the jejunum and ileum and SLC2A2 in the duodenum. Inflammation and morphological changes were observed in the proximal region of the intestine of stressed animals. Compared with jejunal and ileal segments, the rate of increase in TAA was higher in the duodenum, indicating that the segment contained less anti-oxidants; anti-oxidants may function to protect the tissues. In conclusion, stress alters the expression of hexose and lipid transporters in the gut. The site-specific increase in the expression of SLC5A1 and SLC2A2 may be correlated with pathological changes in the intestine. The ileum may be protected, in part, by gut anti-oxidants. Collectively, the data suggest that apart from causing inflammation, chronic stress may promote sugar uptake and contribute to hyperglycaemia.
10.1111/1440-1681.12096
Chronic stress leads to persistent and contrasting stellate neuron dendritic hypertrophy in the amygdala of male and female rats, an effect not found in the hippocampus.
Neuroscience letters
In males, chronic stress enhances dendritic complexity in the amygdala, a region important in emotion regulation. An amygdalar subregion, the basolateral amygdala (BLA), is influenced by the hippocampus and prefrontal cortex to coordinate emotional learning and memory. This study quantified changes in dendritic complexity of BLA stellate neurons ten days after an unpredictable chronic stressor ended in both male and female rats. In addition, dendritic complexity of hippocampal neurons in male rats was assessed at a similar timepoint. Following Golgi processing, stressed male and female rats showed enhanced BLA dendritic complexity; increased arborization occurred near the soma in males and distally in females. As the brain was sampled ten days after chronic stress ended, BLA dendritic hypertrophy persisted in both sexes after the stressor had ended. For the hippocampus, CA3 dendritic complexity was similar for control and stressed males when assessed eight days after stress ended, suggesting that any stress-induced changes had resolved. These results show persistent enhancement of BLA dendritic arborization in both sexes following chronic stress, reveal sex differences in how BLA hypertrophy manifests, and suggest a putative neurobiological substrate by which chronic stress may create a vulnerable phenotype for emotional dysfunction.
10.1016/j.neulet.2023.137403
Chronic restraint stress promotes hepatocellular carcinoma growth by mobilizing splenic myeloid cells through activating β-adrenergic signaling.
Jiang Wei,Li Yu,Li Zhen-Zhen,Sun Jin,Li Jiang-Wei,Wei Wei,Li Liang,Zhang Chen,Huang Chen,Yang Shuan-Ying,Yang Jun,Kong Guang-Yao,Li Zong-Fang
Brain, behavior, and immunity
Psychological stress promotes tumor progression and has a large impact on the immune system, particularly the spleen. The spleen plays an important role in tumor behavior. However, the role and mechanism of the spleen in hepatocellular carcinoma progression induced by stress is unclear. Here, we showed that the spleen plays a critical role in hepatocellular carcinoma growth induced by restraint stress. Our results demonstrated that restraint stress promoted hepatocellular carcinoma growth, changed the spleen structure, and redistributed splenic myeloid cells to tumor tissues. Interestingly, we found that splenectomy could inhibit hepatocellular carcinoma growth and prevent increases in myeloid cells and macrophages in tumor tissues in stressed mice. Restraint stress significantly elevated the concentration of norepinephrine in the spleen, serum and tumor tissues. Meanwhile, propranolol, an inhibitor of β-adrenergic signaling, could inhibit hepatocellular carcinoma growth and prevent the redistribution of splenic myeloid cells induced by restraint stress, suggesting that restraint stress promotes hepatocellular carcinoma growth and redistributes splenic myeloid cells through β-adrenergic signaling. Mechanistic studies revealed that restraint stress upregulated the expressions of CXCL2/CXCL3 in tumor tissues and changed the expression of CXCR2 in myeloid cells. SB225002, an inhibitor of CXCR2, could prevent the recruitment of myeloid cells in tumor tissues and inhibit tumor growth in stressed mice. Together, these data indicate that chronic restraint stress promotes hepatocellular carcinoma growth by mobilizing splenic myeloid cells to tumor tissues via activating β-adrenergic signaling. The CXCR2-CXCL2/CXCL3 axis contributed to the recruitment of myeloid cells in tumor tissues induced by restraint stress.
10.1016/j.bbi.2019.05.031
Neuroprotective Role of Selenium Nanoparticles Against Behavioral, Neurobiochemical and Histological Alterations in Rats Subjected to Chronic Restraint Stress.
Molecular neurobiology
Chronic stress induces changes in the prefrontal cortex and hippocampus. Selenium nanoparticles (SeNPs) showed promising results in several neurological animal models. The implementation of SeNPs in chronic restraint stress (CRS) remains to be elucidated. This study was done to determine the possible protective effects of selenium nanoparticles on behavioral changes and brain oxidative stress markers in a rat model of CRS. 50 rats were divided into three groups; control group (n = 10), untreated CRS group (n = 10) and CRS-SeNPs treated group (n = 30). Restraint stress was performed 6 h./day for 21 days. Rats of CRS-SeNPs treated group received 1, 2.5 or 5 mg/kg SeNPs (10 rats each) by oral gavage for 21 days. Rats were subjected to behavioral assessments and then sacrificed for biochemical and histological analysis of the prefrontal cortex and hippocampus. Prefrontal cortical and hippocampal serotonin levels, oxidative stress markers including malondialdehyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx), tumor necrosis factor alpha (TNF-α) and caspase-3 were assessed. Accordingly, different doses of SeNPs showed variable effectiveness in ameliorating disease parameters, with 2.5 mg/kg dose of SeNPs showing the best improving results in all studied parameters. The present study exhibited the neuroprotective role of SeNPs in rats subjected to CRS and proposed their antioxidant, anti-inflammatory and anti-apoptotic effects as the possible mechanism for increased prefrontal cortical and hippocampal serotonin level, ameliorated anxiety-like and depressive-like behaviors and improved prefrontal cortical and hippocampal histological architecture.
10.1007/s12035-024-04196-3
Effects of arketamine on depression-like behaviors and demyelination in mice exposed to chronic restrain stress: A role of transforming growth factor-β1.
Journal of affective disorders
BACKGROUND:Chronic restrain stress (CRS) induces depression-like behaviors and demyelination in the brain; however, the relationship between these depression-like behaviors and demyelination remains unclear. Arketamine, the (R)-enantiomer of ketamine, has shown rapid antidepressant-like effects in CRS-exposed mice. METHODS:We examined whether arketamine can improve both depression-like behaviors and demyelination in the brains of CRS-exposed mice. Additionally, we investigated the role of transforming growth factor β1 (TGF-β1) in the beneficial effects of arketamine. RESULTS:A single dose of arketamine (10 mg/kg) improved both depression-like behavior and demyelination in the corpus callosum of CRS-exposed mice. Correlations were found between depression-like behaviors and demyelination in this region. Furthermore, pretreatment with RepSox, an inhibitor of TGF-β1 receptor, significantly blocked the beneficial effects of arketamine on depression-like behaviors and demyelination in CRS-exposed mice. Finally, a single intranasal administration of TGF-β1 ameliorated both depression-like behaviors and demyelination in CRS-exposed mice. LIMITATIONS:The precise mechanisms by which TGF-β1 contributes to the effects of arketamine remain unclear. CONCLUSIONS:These data suggest that CRS-induced demyelination in the corpus callosum may contribute to depression-like behaviors, and that arketamine can mitigate these changes through a TGF-β1-dependent mechanism.
10.1016/j.jad.2024.08.222
Acupuncture Ameliorates Depression-Like Behaviors Through Modulating the Neuroinflammation Mediated by TLR4 Signaling Pathway in Rats Exposed to Chronic Restraint Stress.
Molecular neurobiology
Recently, emerging evidence has identified that stress-induced activation of neuroinflammation is considered to be one of the most prevalently precipitating factors in the pathogenesis of depression. Data from clinical trials and experimental findings has verified the efficacy and safety of acupuncture in the prevention and treatment of depression. However, the mechanism of the preventive effect of acupuncture for depression has not been fully elucidated. The current study aimed to investigate the preventive effect and mechanism of acupuncture through modulating the neuroinflammation mediated by toll-like receptor 4 (TLR4) signaling pathway in rats exposed to chronic restraint stress (CRS). All rats were subjected to CRS for 21 days, with the exception of rats in control group. One hour before CRS, rats in acupuncture group were exposed to acupuncture at Baihui (GV20) and Yintang (GV29). The depression-like behaviors were evaluated by body weight assessment and sucrose preference test at 0, 7, 14, and 21 days. The expression of activated microglia in hippocampus was detected by immunofluorescence. The expression of key proteins on TLR4 signaling pathway of TLR4, MyD88, TRAF6, NF-κB p65, TNF-α, and mRNA of TLR4 in the hippocampus was detected by western blot and real-time quantitative polymerase chain reaction to investigate the effect of acupuncture on stress-induced activation of neuroinflammation. The present study provided evidence that acupuncture exerted potential preventive effect that might be mediated in part by suppressing the neuroinflammation induced by TLR4 signaling pathway, which may be a promising treatment target to improve current treatments for depression.
10.1007/s12035-023-03737-6
The effects of chronic restraint stress on empathy-like behaviour in rats.
Sen Aysu,Kara Ali Yucel,Koyu Ahmet,Simsek Fatma,Kizildag Servet,Uysal Nazan
Neuroscience letters
It is clearly known that psychological stress is an important threat to health in today's modern societies. Recent studies have shown that acute stress causes an increase in positive social behaviours such as prosocial behaviour and devotion which are components of empathic behaviour. Neuropsychiatric manifestations such as anxiety and depression may affect empathic behaviour. The aim of this study was to investigate the effects of chronic restraint stress on empathy-like behaviour and the histopathological changes in the amygdala, prefrontal cortex in the adrenal glands and thymus, as well as the neurochemical pathways associated with empathy, oxytocin and vasopressin. The chronic stress group was subjected to restraint stress daily for 14 days after all subjects were trained to rescue its stressed cagemate using empathy test equipment for 12 days. It was observed that chronic restraint stress had no effect on empathy-like behaviour in rats. Vasopressin levels in amygdala was increased in chronic stress group compared to control group. Anxiety and depression indicators did not change in both groups. In the open field test, control group spent more time in thigmo zone compared to chronic stress group. Adrenal glands relative weights and apoptotic cell ratios were significantly higher in the chronic stress group compared to the control group (expectedly). Although there was no significant difference in behavioral tests, histopathological changes were detected. In subsequent studies, it is appropriate to examine the effects of different types of stress applications, gender-related changes, and other neurochemical pathways associated with stress and empathy.
10.1016/j.neulet.2021.136255