scholarly journals Chronic Stress and Gonadectomy Affect the Expression of Cx37, Cx40 and Cx43 in the Spinal Cord

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1330
Author(s):  
Marija Jurić ◽  
Marta Balog ◽  
Vedrana Ivić ◽  
Benjamin Benzon ◽  
Anita Racetin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Chronic Stress ◽  
Pain Perception ◽  
Female Rats ◽  
Male Rats ◽  
Stress Exposure ◽  
Cx43 Expression ◽  
Stressed Group ◽  
Transmission Electron ◽  
Chronic Pain Conditions

The study aimed to determine whether the exposure to chronic stress and/or performance of gonadectomy might lead to disturbance in the expression of connexin (Cx) 37, 40 and 43 in the spinal cord (SC), as a potential explanation for sex differences in stress-related chronic pain conditions. After the rats were sham-operated or gonadectomized, three 10-day sessions of sham or chronic stress were applied. Immunohistochemistry and transmission electron microscopy (TEM) were used to examine Cx localization and expression in the SC. The gonadectomy resulted in an increase of Cx37 expression in the dorsal horn (DH) of the female rats, but chronic stress suppressed the effects of castration. In male rats, only the combined effects of castration and chronic stress increased Cx37 expression. The influence of chronic stress on the DH Cx40 expression was inversely evident after the castration: increased in the ovariectomized female rats, while decreased in the orchidectomized male rats. We did not find any effect of chronic stress and castration, alone or together, on Cx43 expression in the DH, but the percentage of Cx43 overlapping the astrocyte marker glial fibrillary acidic protein (gfap) increased in the male stressed group after the castration. In conclusion, the association of the chronic stress with sex hormone depletion results in disturbances of the SC Cx expression and might be a possible mechanism of disturbed pain perception after chronic stress exposure.

scholarly journals Pair-housing of male and female rats during chronic stress exposure results in gender-specific behavioral responses

2005 ◽  
Vol 47 (5) ◽  
pp. 620-628 ◽  
Author(s):  
C. Westenbroek ◽  
T.A.B. Snijders ◽  
J.A. den Boer ◽  
M. Gerrits ◽  
D.S. Fokkema ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Behavioral Responses ◽  
Female Rats ◽  
Stress Exposure ◽  
Male And Female ◽  
Male And Female Rats ◽  
Gender Specific

scholarly journals Facilitation of the HPA Axis to a Novel Acute Stress Following Chronic Stress Exposure Modulates Histone Acetylation and the ERK/MAPK Pathway in the Dentate Gyrus of Male Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 2942-2952 ◽  
Author(s):  
Chantelle L. Ferland ◽  
Erin P. Harris ◽  
Mai Lam ◽  
Laura A. Schrader
Keyword(s):  
Dentate Gyrus ◽  
Histone Acetylation ◽  
Chronic Stress ◽  
Hpa Axis ◽  
Acute Stress ◽  
Male Rats ◽  
Stress Exposure ◽  
Erk Activation ◽  
Acute And Chronic Stress ◽  
Acute Stressor

Evidence suggests that when presented with novel acute stress, animals previously exposed to chronic homotypic or heterotypic stressors exhibit normal or enhanced hypothalamic-pituitary-adrenal (HPA) response compared with animals exposed solely to that acute stressor. The molecular mechanisms involved in this effect remain unknown. The extracellular signal-regulated kinase (ERK) is one of the key pathways regulated in the hippocampus in both acute and chronic stress. The aim of this study was to examine the interaction of prior chronic stress, using the chronic variable stress model (CVS), with exposure to a novel acute stressor (2,5-dihydro-2,4,5-trimethyl thiazoline; TMT) on ERK activation, expression of the downstream protein BCL-2, and the glucocorticoid receptor co-chaperone BAG-1 in control and chronically stressed male rats. TMT exposure after chronic stress resulted in a significant interaction of chronic and acute stress in all 3 hippocampus subregions on ERK activation and BCL-2 expression. Significantly, acute stress increased ERK activation, BCL-2 and BAG-1 protein expression in the dentate gyrus (DG) of CVS-treated rats compared with control, CVS-treated alone, and TMT-only animals. Furthermore, CVS significantly increased ERK activation in medial prefrontal cortex, but acute stress had no significant effect. Inhibition of corticosterone synthesis with metyrapone had no significant effect on ERK activation in the hippocampus; therefore, glucocorticoids alone do not mediate the molecular effects. Finally, because post-translational modifications of histones are believed to play an important role in the stress response, we examined changes in histone acetylation. We found that, in general, chronic stress decreased K12H4 acetylation, whereas acute stress increased acetylation. These results indicate a molecular mechanism by which chronic stress-induced HPA axis plasticity can lead to neurochemical alterations in the hippocampus that influence reactivity to subsequent stress exposure. This may represent an important site of dysfunction that contributes to stress-induced pathology such as depression, anxiety disorders, and posttraumatic stress disorder.

THE INFLUENCE OF SEX ON THE MATURATION OF THE CENTRAL NERVOUS SYSTEM IN THE ALBINO RAT

1951 ◽  
Vol 7 (3) ◽  
pp. 271-279 ◽  
Author(s):  
J. T. EAYRS
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
The Body ◽  
Female Rats ◽  
Male Rats ◽  
Albino Rat ◽  
Litter Mate ◽  
Male And Female Rats ◽  
The Central Nervous System

The growth of the body and central nervous system and the emergence of stereotyped behaviour have been studied in male and female rats during the first 24 days of life. The effects of daily injections of equine gonadotrophin on these measures have also been investigated. The weight of the body and of the central nervous system was significantly less in the female than in the male. The daily administration of 10 i.u. of equine gonadotrophin was without effect on either. The movements of the trunk and limbs concerned in the body-righting reflex became coordinated more slowly in the gonadotrophin-injected animals than in their litter-mate controls. At 15 days old, male rats were able to right in mid-air more successfully than litter-mate females. The placing reflex appeared earlier in the male than in the female. Its appearance was accelerated in the females given gonadotrophin, but not in the males. In the ventral funiculus of the spinal cord of 24-day-old experimental animals, the axis cylinders occupied more space relative to that occupied by myelin than did those of the controls. The total amount of myelin present was unchanged. There was no sex difference in the progress of myelination in the spinal cord. The significance of these findings in relation to the secretion of sex hormones is discussed. It is suggested that the secretion of androgen may be responsible for an acceleration of nervous maturation.

The effect of 2,3,4 trimethylpentane on the ultrastructure of kidneys from normal versus castrated male rats

1986 ◽  
Vol 44 ◽  
pp. 356-357
Author(s):  
D.R. Mattie ◽  
M.R. Chase ◽  
D.W. Hobson
Keyword(s):  
Principal Component ◽  
Female Rats ◽  
Male Rats ◽  
Low Molecular Weight ◽  
Cell Degeneration ◽  
Protein Deposition ◽  
Transmission Electron ◽  
Kidney Lesion ◽  
Proximal Tubular ◽  
Kidney Lesions

Studies in this laboratory have shown that exposure to vapors of hydrocarbon fuels such as JP-5, JP-4 and diesel fuel-marine produce kidney lesions, including protein deposition, proximal tubular cell degeneration and intratubular casts in male rats, but not in female rats. 2,2,4 trimethylpentane (TMP) is a principal component of gasoline. Both 2,2,4 TMP and its more potent isomer, 2,3,4 TMP, in gavage studies produced Kidney lesions identical to those seen in acute fuel inhalation exposures. Only male rats produce a testosterone dependent alpha 2u globulin, a low molecular weight plasma protein. Since this protein appears to be involved in the pathogenesis of the kidney lesion, castrated rats were also exposed to 2,3,4 TMP and examined by transmission electron microscopy.

scholarly journals Juvenile exposure to acute traumatic stress leads to long-lasting alterations in grey matter myelination in adult female but not male rats

2020 ◽  
Author(s):  
Jocelyn M Breton ◽  
Matthew Barraza ◽  
Kelsey Y Hu ◽  
Samantha Joy Frias ◽  
Kimberly L.P. Long ◽  
...  
Keyword(s):  
Traumatic Stress ◽  
Grey Matter ◽  
Acute Stress ◽  
Brain Regions ◽  
Adult Brain ◽  
Female Rats ◽  
Male Rats ◽  
Stress Exposure ◽  
Corticosterone Release

Stress early in life can have a major impact on brain development, and there is increasing evidence that childhood stress confers vulnerability for later developing psychiatric disorders. In particular, during peri-adolescence, brain regions crucial for emotional regulation, such as the prefrontal cortex (PFC), amygdala (AMY) and hippocampus (HPC), are still developing and are highly sensitive to stress. Changes in myelin levels have been implicated in mental illnesses and stress effects on myelin and oligodendrocytes (OLs) are beginning to be explored as a novel and underappreciated mechanism underlying psychopathologies. Yet there is little research on the effects of acute stress on myelin during peri-adolescence, and even less work exploring sex-differences. Here, we used a rodent model to test the hypothesis that exposure to acute traumatic stress as a juvenile would induce changes in OLs and myelin content across limbic brain regions. Male and female juvenile rats underwent three hours of restraint stress with exposure to a predator odor on postnatal day (p) 28. Acute stress induced a physiological response, increasing corticosterone release and reducing weight gain in stress-exposed animals. Brain sections containing the PFC, AMY and HPC were taken either in adolescence (p40), or in adulthood (p95) and stained for markers of OLs and myelin. We found that acute stress induced sex-specific changes in grey matter (GM) myelination and OLs in both the short- and long-term. Exposure to a single stressor as a juvenile increased GM myelin content in the AMY and HPC in p40 males, compared to the respective control group. At p40, corticosterone release during stress exposure was also positively correlated with GM myelin content in the AMY of male rats. Single exposure to juvenile stress also led to long-term effects exclusively in female rats. Compared to controls, stress-exposed females showed reduced GM myelin content in all three brain regions. Acute stress exposure decreased PFC and HPC OL density in p40 females, perhaps contributing towards this observed long-term decrease in myelin content. Overall, our findings suggest that the juvenile brain is vulnerable to exposure to a brief severe stressor. Exposure to a single short traumatic event during peri-adolescence produces long-lasting changes in GM myelin content in the adult brain of female, but not male, rats. These findings highlight myelin plasticity as a potential contributor to sex-specific sensitivity to perturbation during a critical window of development.

scholarly journals Evidence for Similar Prefrontal Structural and Functional Alterations in Male and Female Rats Following Chronic Stress or Glucocorticoid Exposure

2019 ◽  
Vol 30 (1) ◽  
pp. 353-370 ◽  
Author(s):  
Rachel M Anderson ◽  
Shane B Johnson ◽  
Ryan T Lingg ◽  
Dalton C Hinz ◽  
Sara A Romig-Martin ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Dendritic Spine ◽  
Pyramidal Neurons ◽  
Female Rats ◽  
Male Rats ◽  
Sexually Dimorphic ◽  
Stress Effects ◽  
Male And Female Rats ◽  
Males And Females ◽  
And Function

Abstract Previous work of ours and others has documented regressive changes in neuronal architecture and function in the medial prefrontal cortex (mPFC) of male rats following chronic stress. As recent focus has shifted toward understanding whether chronic stress effects on mPFC are sexually dimorphic, here we undertake a comprehensive analysis to address this issue. First, we show that chronic variable stress (14-day daily exposure to different challenges) resulted in a comparable degree of adrenocortical hyperactivity, working memory impairment, and dendritic spine loss in mPFC pyramidal neurons in both sexes. Next, exposure of female rats to 21-day regimen of corticosterone resulted in a similar pattern of mPFC dendritic spine attrition and increase in spine volume. Finally, we examined the effects of another widely used regimen, chronic restraint stress (CRS, 21-day of daily 6-h restraint), on dendritic spine changes in mPFC in both sexes. CRS resulted in response decrements in adrenocortical output (habituation), and induced a pattern of consistent, but less widespread, dendritic spine loss similar to the foregoing challenges. Our data suggest that chronic stress or glucocorticoid exposure induces a relatively undifferentiated pattern of structural and functional alterations in mPFC in both males and females.

Stress-induced prolactin release in female, male and androgenized rats: influence of progesterone treatment

1986 ◽  
Vol 110 (3) ◽  
pp. 423-428 ◽  
Author(s):  
G. A. Jahn ◽  
R. P. Deis
Keyword(s):  
Luteal Phase ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Serum Prolactin ◽  
Maternal Behaviour ◽  
Stress Exposure ◽  
Control Groups ◽  
Prolactin Release ◽  
Serum Progesterone

ABSTRACT Ether stress applied at 10.00 h induced a 100% increase in serum prolactin in intact and ovariectomized androgenized rats. Ovariectomy significantly diminished the basal serum prolactin values observed in intact androgenized rats. Two doses of progesterone (5 mg) given to intact and ovariectomized androgenized rats 14 and 2 h before exposure to ether stress increased prolactin values in the control groups but completely prevented the effect of stress. Exposure to ether stress induced a 100% increase in serum prolactin values in androgenized rats with increased serum progesterone levels 4 days after the induction of ovulation and the luteal phase with human chorionic gonadotropin (hCG). A group of androgenized rats with induced maternal behaviour and which had been suckled for 6 days was given 100 i.u. hCG and suckled for another 6 days after the hCG-induced luteal phase had been established. The serum prolactin and progesterone values of these rats were significantly higher than those treated with hCG only and ether stress did not increase prolactin release. A greatly increased serum concentration of prolactin was obtained in pro-oestrous and oestrous virgin rats after exposure to ether stress. Serum prolactin was also increased by stress in male rats. Progesterone administration to these female and male rats prevented stress-induced prolactin release. To ascertain the part played by dopamine and serotonin in the effect of stress on prolactin release, groups of androgenized and oestrous female rats were treated with bromocriptine or p-chlorophenylalanine methylester hydrochloride (pCPA). The dopaminergic agonist bromocriptine markedly reduced prolactin levels in the unstressed androgenized rats, but did not prevent the prolactin increases induced by stress. Administration of pCPA had no effect on basal or stress-increased serum levels of prolactin. It is concluded that modifications of the ovarian steroid secretions, especially of progesterone, has profound effects on prolactin release in response to ether stress. The release of the hormone was not mediated by a dopaminergic or serotonergic regulatory pathway. J. Endocr. (1986) 110, 423–428

scholarly journals Effect of Cold Stress on Neurobehavioral and Physiological Parameters in Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Hajar El Marzouki ◽  
Youssef Aboussaleh ◽  
Mohamed Najimi ◽  
Fatiha Chigr ◽  
Ahmed Ahami
Keyword(s):  
Working Memory ◽  
Object Recognition ◽  
Food Intake ◽  
Cold Stress ◽  
Chronic Stress ◽  
Cold Exposure ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female Rats ◽  
Y Maze

Objective: Cold stress is an important current issue and implementing control strategies to limit its sometimes harmful effects is crucial. Cold is a common stressor that can occur in our work and our occupational or leisure time activities every day. There are substantial studies on the effects of chronic stress on memory and behavior, although, the cognitive changes and anxiety disorders that can occur after exposure to chronic intermittent cold stress are not completely characterized. Therefore, the present study was undertaken with an aim to investigate the effects of chronic intermittent cold stress on body weight, food intake and working memory, and to elucidate cold stress related anxiety disorders using cognitive and behavioral test batteries.Methods: We generated a cold stress model by exposing rats to chronic intermittent cold stress for 5 consecutive days and in order to test for the potential presence of sex differences, a comparable number of male and female rats were tested in the current study. Then, we measured the body weights, food intake and the adrenal glands weight. Working memory and recognition memory were assessed using the Y maze and the Novel Object Recognition (NOR) tasks. While, sex differences in the effects of chronic stress on behavior were evaluated by the elevated plus maze (EPM), open field maze (OF), and Marble burying (MB) tests.Results: We found that 2 h exposure to cold (4°C) resulted in an increase in the relative weight of the adrenal glands in male rats. Given the same chronic stress 5 days of cold exposure (2 h per day), increased weight gain in male rats, while females showed decreased food intake and no change in body weight. Both sexes successfully performed the Y maze and object recognition (OR) tasks, indicating intact spatial working memory performance and object recognition abilities in both male and female rats. In addition, we have shown that stress caused an increase in the level of anxiety in male rats. In contrast, the behavior of the female rats was not affected by cold exposure.Conclusion: Overall, the current results provide preliminary evidence that chronic intermittent cold stress model may not be an efficient stressor to female rats. Females exhibit resilience to cold exposure that causes an increase in the level of anxiety in male rats, which demonstrates that they are affected differently by stress and the gender is an important consideration in experimental design.

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