scholarly journals Maternal Experience Does Not Predict Fear Extinction and Anxiety-Like Behaviour in Primiparous Rats Post-weaning

2021 ◽  
Vol 2 ◽  
Author(s):  
Jodie E. Pestana ◽  
Tayla B. McCutcheon ◽  
Sylvia K. Harmon-Jones ◽  
Rick Richardson ◽  
Bronwyn M. Graham
Keyword(s):  
Estrous Cycle ◽  
Sex Hormones ◽  
Past Research ◽  
Fear Extinction ◽  
Female Rats ◽  
Laboratory Model ◽  
Maternal Behaviour ◽  
Reproductive Experience ◽  
Maternal Experience ◽  
The Impact

Reproductive experience leads to long-lasting changes in anxiety-like behaviour and fear extinction, the laboratory model of exposure therapy for anxiety disorders. For example, fear extinction is influenced by estrous cycle in nulliparous (no reproductive experience) female rats, but this effect is abolished in primiparous (one reproductive experience) females. It is unclear whether such changes are driven by pregnancy, maternal experience of caring for offspring during the postpartum period, or a combination of both experiences. The present study sought to determine the influence of maternal experience (i.e., exposure to pups and mother-pup interactions) on fear extinction in primiparous rats. In Experiment 1, we tested whether pup exposure is necessary to mitigate estrous effects on fear extinction in primiparous rats. Age-matched nulliparous rats, primiparous rats, and primiparous rats who experienced pregnancy but not pup exposure, underwent fear conditioning on day 1 (2 months post-parturition), extinction training during proestrus (high sex hormones) or metestrus (low sex hormones) on day 2, and extinction recall on day 3. Replicating past research, nulliparous rats showed impaired extinction recall when they were extinguished during metestrus compared to proestrus. In contrast, primiparous rats with and without pup exposure showed comparable extinction recall irrespective of estrous phase. In Experiment 2, we assessed whether naturally-occurring variation in mother-pup interactions predict future fear extinction performance and anxiety-like behaviour. During the first week of lactation, primiparous rats were measured for maternal behaviours toward pups. Primiparous rats were then tested on the light-dark box and elevated plus maze to measure anxiety-like behaviour and underwent a fear extinction protocol 1 month post-weaning. We found no significant correlations between maternal behaviour and fear extinction outcomes or anxiety-like behaviour. Our findings suggest that pregnancy, not maternal experience, mitigates the impact of estrous cycle on fear extinction. In addition, natural variation in maternal experience does not appear to contribute to variability in future fear extinction outcomes or anxiety-like behaviour in primiparous rats.

scholarly journals Expression and function of nesfatin-1 are altered by stage of the estrous cycle

2019 ◽  
Vol 317 (2) ◽  
pp. R328-R336 ◽  
Author(s):  
Alicia T. Pate ◽  
Abigayle L. Schnell ◽  
Teresa A. Ennis ◽  
Willis K. Samson ◽  
Gina L. C. Yosten
Keyword(s):  
Angiotensin Ii ◽  
Estrous Cycle ◽  
Sex Hormones ◽  
Cardiovascular Effects ◽  
Female Rats ◽  
Male Rats ◽  
Melanocortin Receptors ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
And Function

Nesfatin-1 is a peptide derived from the nucleobindin 2 ( Nucb2) precursor protein that has been shown to exert potent effects on appetite and cardiovascular function in male animals. Sex hormones modulate the expression of Nucb2 in several species, including goldfish, mouse, and rat, and human studies have revealed differential expression based on male or female sex. We therefore hypothesized that the ability of nesfatin-1 to increase mean arterial pressure (MAP) would be influenced by stage of the estrous cycle. Indeed, we found that in cycling female Sprague-Dawley rats, nesfatin-1 induced an increase in MAP on diestrus, when both estrogen and progesterone levels are low but not on proestrus or estrus. The effect of nesfatin-1 on MAP was dependent on functional central melanocortin receptors, because the nesfatin-1-induced increase in MAP was abolished by pretreatment with the melanocortin 3/4 receptor antagonist, SHU9119. We previously reported that nesfatin-1 inhibited angiotensin II-induced water drinking in male rats but found no effect of nesfatin-1 in females in diestrus. However, nesfatin-1 enhanced angiotensin II-induced elevations in MAP in females in diestrus but had no effect on males. Finally, in agreement with previous reports, the expression of Nucb2 mRNA in hypothalamus was significantly reduced in female rats in proestrus compared with rats in diestrus. From these data we conclude that the function and expression of nesfatin-1 are modulated by sex hormone status. Further studies are required to determine the contributions of chromosomal sex and individual sex hormones to the cardiovascular effects of nesfatin-1.

Taste reactivity responses in rats: influence of sex and the estrous cycle

1998 ◽  
Vol 274 (3) ◽  
pp. R718-R724 ◽  
Author(s):  
Sharon N. D. A. Clarke ◽  
Klaus-Peter Ossenkopp
Keyword(s):  
Estrous Cycle ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Taste Reactivity ◽  
Male And Female ◽  
Food Items ◽  
Reactivity Test ◽  
The Impact

Gonadal hormones (e.g., estradiol) may regulate feeding by producing a shift in the taste or palatability of food items. This study examined the impact of endogenous gonadal hormones on palatability by investigating sex differences in taste responsivity, as well as the effect of the estrous cycle on taste responsivity, in a rodent model. In the taste reactivity test, male and female Long-Evans rats received a brief (1 min) intraoral infusion of one of three tastants: sucrose (0.3 M), quinine (0.0003 M), and a sucrose-quinine mixture (0.3 M sucrose and 0.0003 M quinine). Statistical analyses indicated that female rats tested during diestrus or proestrus produced significantly more ingestive responses than did male rats and fewer aversive responses than did both male rats and female rats tested during estrus or metestrus ( P < 0.05). These results indicate a sex difference in taste responsivity in the rat that is modulated by the reproductive status of female rats. This finding implies a role of gonadal hormones in the regulation of taste responsivity in the rat.

Influence of gender and estrous cycle on plasma and renal catecholamine levels in rats

2012 ◽  
Vol 90 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Helena L. Gomes ◽  
Jones B. Graceli ◽  
Washington L.S. Gonçalves ◽  
Roger L. dos Santos ◽  
Gláucia R. Abreu ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Wistar Rats ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Plasma Catecholamine ◽  
Nandrolone Decanoate ◽  
Estrogen Replacement ◽  
Male And Female ◽  
The Impact ◽  
Catecholamine Levels

Several studies have demonstrated that gonadal hormones show significant effects on the brain and signaling pathways of effector organs/cells that respond to neurotransmitters. Since little information is available concerning the impact of male and female gonadal hormones on the renal and peripheral sympathetic system, the objective of this study was to further assess whether and how the renal content and plasma concentration of catecholamines are influenced by gender and the estrous cycle in rats. To achieve this, males Wistar rats were divided into 4 groups: (i) sham (i.e., control), (ii) gonadectomized, (iii) gonadectomized and nandrolone decanoate replacement at physiological levels or (iv) gonadectomized and nandrolone decanoate replacement at high levels. Female Wistar rats were divided into 6 groups: (i) ovariectomized (OVX), (ii) estrogen replacement at physiological levels and (iii) estrogen replacement at at high levels, (iv) progesterone replacement at physiological levels and (v) progesterone replacement at at high levels, and (vi) sham. The sham group was subdivided into four subgroups: (i) proestrus, (ii) estrus, (iii) metaestrus, and (iv) diestrus. Ten days after surgery, the animals were sacrificed and their plasma and renal catecholamine levels measured for intergroup comparisons. Gonadectomy led to an increase in the plasma catecholamine concentration in females, as well as in the renal catecholamine content of both male and female rats. Gonadectomized males also showed a lower level of plasma catecholamine than the controls. The urinary flow, and the fractional excretion of sodium and chloride were significantly increased in gonadectomized males and in the OVX group when compared with their respective sham groups.

scholarly journals Chronic Stress Detrimentally Affects In Vivo Maturation in Rat Oocytes and Oocyte Viability at All Phases of the Estrous Cycle

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2478
Author(s):  
Fahiel Casillas ◽  
Miguel Betancourt ◽  
Lizbeth Juárez-Rojas ◽  
Yvonne Ducolomb ◽  
Alma López ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Chronic Stress ◽  
Oocyte Maturation ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Female Rats ◽  
Female Reproduction ◽  
The Impact

Background: Stress has been considered as one of the causes of decreased reproductive function in women. However, direct evidence of the effect of chronic stress on oocytes depending on estrous cycle phases is limited. Objective: The present study aimed to evaluate the impact of chronic stress on the viability, integrity, and maturation of rat oocytes depending on estrous cycle phases, specifically proestrus, estrus, and diestrus. Methods: For this purpose, adult female rats were stressed daily by cold water immersion (15 °C) for 30 consecutive days. Results: In chronically stressed female rats, irregular estrous cyclicity, increased corticosterone levels, decreased oocyte viability, and an increased percentage of abnormal oocytes were obtained in all the estrous cycle phases, resulting in reduced oocyte maturation during proestrus. Conclusion: Oocyte maturation disturbed by chronic stress is a crucial factor by which chronic stress disrupts female reproduction

Sexual dimorphism of the intracellular heat shock protein 72 response

2006 ◽  
Vol 101 (2) ◽  
pp. 566-575 ◽  
Author(s):  
M. Nickerson ◽  
S. L. Kennedy ◽  
J. D. Johnson ◽  
M. Fleshner
Keyword(s):  
Sexual Dimorphism ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Estrous Cycle ◽  
Stress Responses ◽  
Female Rats ◽  
Vaginal Smear ◽  
Mesenteric Lymph Nodes ◽  
Males And Females ◽  
The Impact

The majority of previous work examining stress responses has been done in males. Recently, it has become clear that the impact of stressor exposure is modulated by sex. One stress response that may be affected by sex is the induction of intracellular heat shock protein (HSP) 72, which is a stress- responsive molecular chaperone that refolds denatured proteins and promotes cellular survival. The following study compared HSP72 in males and females and also examined whether the estrous cycle altered HSP72 induction in females. We hypothesized that females compared with males would have a constrained HSP72 response after an acute stressor and that the stress-induced HSP72 response in females would fluctuate with the estrous cycle. Male and female F344 rats were either left in their home cage or exposed to acute tail-shock stress (8–10/group). Immediately following stressor, trunk blood was collected and tissues were flash frozen. Vaginal smear and estrogen enzyme immunoassay were used to categorize the phase of estrous. Results show that female rats had a greater corticosterone response than males, that both males and females exhibit a stress-induced release of progesterone, and that males and females had equal levels of stress-induced circulating norepinephrine. Sexual dimorphism of the HSP72 (ELISA) response existed in pituitary gland, mesenteric lymph nodes, and liver such that female rats had an attenuated HSP72 response compared with males after stress. The adrenal glands, spleen, and heart did not exhibit sexual dimorphism of the HSP72 response. The estrous cycle did not have a significant effect on basal or stress-induced HSP72 in females.

scholarly journals Pathophysiological Changes in Female Rats with Estrous Cycle Disorder Induced by Long-Term Heat Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
GaiHong An ◽  
XueWei Chen ◽  
Chao Li ◽  
Li Zhang ◽  
MengFan Wei ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Estrous Cycle ◽  
Underlying Mechanism ◽  
Female Rats ◽  
Stable Model ◽  
Sprague Dawley ◽  
Pathological Characteristics ◽  
The Impact

High-temperature exposure is detrimental to women’s reproductive health; however, the impact caused by long-term high temperature is not comprehensive, and a stable model of estrous cycle disorder induced by a high temperature is yet lacking. Herein, we aimed to establish a stable and effective model of estrous cycle disorder in female rats induced by long-term heat stress to study its physiological and pathological characteristics and explore the underlying mechanism. In the present study, female Sprague-Dawley rats with normal estrous cycles were exposed to the temperature of 38±0.5°C, relative humidity (RH) of 55±5% (2 h/d, 1 time/d) hot cabin at more than 90 days. Consequently, after long-term heat stress, no difference was detected in body weight and rectal temperature, but the estrus cycle was prolonged, the uterine organ index was increased, pathological changes occurred, the increase latitude of stress hormones heat shock protein 70 (Hsp70) and corticosterone (CORT) decreased, estradiol (E2) and luteinizing hormone (LH) levels decreased, follicle stimulating hormone (FSH) and prolactin (Prl) levels increased, gonadotropin-releasing hormone (GnRH) and thyroid hormone (T4) showed no difference, and insulin (INS) decreased significantly. Moreover, the mRNA expression of the sex hormone receptor in the uterus and ovary was altered. Therefore, the estrous cycle disorder in female rats can be induced by regular heat stress for 90 days, which can be considered the pioneer method. Subsequently, prominent physiological and pathological characteristics and disruption in the hypothalamic-pituitary-gonadal (HPG) axis were noted.

Assessment of Superoxide Dismutase and Catalase Evolution in Different Stages of an Experimental Endometriosis

2017 ◽  
Vol 68 (6) ◽  
pp. 1381-1383
Author(s):  
Allia Sindilar ◽  
Carmen Lacramioara Zamfir ◽  
Eusebiu Viorel Sindilar ◽  
Alin Constantin Pinzariu ◽  
Eduard Crauciuc ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Reproductive Function ◽  
Female Rats ◽  
Oxygen Species ◽  
Efficient Treatment ◽  
Endometrial Cells ◽  
Gynecological Disorder ◽  
The Impact

Endometriosis is described as a gynecological disorder characterized by the presence of endometrial tissue outside the uterus; extensively explored because of its increasing incidency, with an indubitable diagnostic only after invasive surgery, with no efficient treatment, it has still many aspects to be elucidated. A growing body of facts sustain oxidative stress as a crucial factor between the numerous incriminated factors implicated in endometriosis ethiopathogeny. Reactive oxygen species(ROS) act to decline reproductive function. Our study intends to determine if an experimental model of endometriosis may be useful to assess the impact of oxidative stress on endometrial cells; we have used a murine model of 18 adult Wistar female rats. A fragment from their left uterine horn was implanted in the abdominal wall. After 4 weeks, a laparatomy was performed, 5 endometrial implants were removed, followed by biochemical tissue assay of superoxide dismutase(SOD) and catalase(CAT). At the end of the experiment, the rats were sacrificed, the implants were removed for histopathological exam and biochemical assay of antioxidant enzymes. The results revealed decreased levels of antioxidant enzymes, pointing on significant oxidative stress involvement.

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