scholarly journals Expression patterns of Arc mRNA after renewal of appetitive behavior in female rats.

2021 ◽  
Author(s):  
Emily N Hilz ◽  
Laura A Agee ◽  
Donyun S Jun ◽  
Marie H Monfils ◽  
Hongjoo J Lee
Keyword(s):  
Estrous Cycle ◽  
Expression Patterns ◽  
Neuronal Population ◽  
Extinction Training ◽  
Female Rats ◽  
Early Gene ◽  
Female Rat ◽  
Appetitive Behavior ◽  
Neuronal Populations ◽  
Estrous Cycle Stage

Renewal of appetitive behavior depends on the gonadal hormonal state of the female rat. In this experiment the effect of female rat estrous cycle stage on renewal of appetitive behaviors is replicated and extended upon to understand how endogenous hormonal states around the estrous cycle drive renewal at the neuronal population level. Estrous cycle stage (i.e., proestrus (P, high hormone) or metestrus/diestrus (M/D, low hormone)) was considered during two important learning and behavioral expression windows: at extinction training and during LTM/renewal testing. First, rats in P during context-dependent extinction training but in some other stage of the estrous cycle during long-term memory and renewal testing (Different) were shown to exhibit more renewal of conditioned foodcup (but not conditioned orienting) behavior compared to rats in other estrous cycle groups. Next, cellular compartment analysis of temporal activity using fluorescence in situ hybridization (catFISH) was used to examine immediate early gene activity of Arc mRNA in neuronal populations after distinct context-stimulus exposures (i.e., extinction and acquisition test contexts). Arc mRNA expression patterns were examined in the prefrontal cortex (PFC), amygdala, hippocampus (HPC), and paraventricular nucleus of the thalamus. P-different rats showed differential neuronal population activity in the infralimbic cortex of the PFC, the lateral amygdaloid nucleus, and both CA1 and CA3 regions of the dorsal HPC. In each region P-different rats exhibited more co-expression and less specificity of Arc mRNA compared to other hormonal groups, indicating that renewal of appetitive foodcup behavior induces Arc mRNA in overlapping neuronal populations in female rats.

Estrous Cycle Modulation of Feeding and Relaxin-3/Rxfp3 mRNA Expression - Implications for Estradiol

2020 ◽  
Author(s):  
Camila de Ávila ◽  
Sandrine Chometton ◽  
Juliane Calvez ◽  
Geneviève Guèvremont ◽  
Alan Kania ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Food Intake ◽  
Estrous Cycle ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Female Rats ◽  
Type I ◽  
Mrna Levels ◽  
Female Rat ◽  
Relaxin Family

Introduction: Food intake varies during the ovarian hormone/estrous cycle in humans and rodents, an effect mediated mainly by estradiol. A potential mediator of the central anorectic effects of estradiol is the neuropeptide relaxin-3 (RLN3) synthetised in the nucleus incertus (NI) and acting via the relaxin-family peptide-3 receptor (RXFP3). Methods: We investigated the relationship of RLN3/RXFP3 signaling and feeding behavior across the female rat estrous cycle. We used in situ hybridization to investigate expression patterns of Rln3 mRNA in NI and Rxfp3 mRNA in the hypothalamic paraventricular nucleus (PVN), lateral hypothalamic area (LHA), medial preoptic area (MPA), and bed nucleus of the stria terminalis (BNST), across the estrous cycle. We identified expression of estrogen receptors in the NI using droplet digital polymerase-chain reaction and assessed the electrophysiological responsiveness of NI neurons to estradiol in brain slices. Results: Rln3 mRNA reached the lowest levels in the NI pars compacta during proestrus. Rxfp3 mRNA levels varied across the estrous cycle in a region-specific manner, with changes observed in the perifornical LHA, magnocellular PVN, dorsal BNST, and MPA, but not in the parvocellular PVN or lateral LHA. G protein-coupled estrogen receptor-1 (Gper1) mRNA was the most abundant estrogen receptor transcript in the NI. Estradiol inhibited 33% of type I NI neurons, including RLN3-positive cells. Conclusion: These findings demonstrate that the RLN3/RXFP3 system is modulated by the estrous cycle and although further studies are required to better elucidate the cellular and molecular mechanisms of estradiol signaling, current results implicate the involvement of RLN3/RXFP3 system in food intake fluctuations observed across the estrous cycle in female rats.

scholarly journals Local Cerebral Glucose Utilization in Normal Female Rats: Variations during the Estrous Cycle and Comparison with Males

1985 ◽  
Vol 5 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Astrid Nehlig ◽  
Linda J. Porrino ◽  
Alison M. Crane ◽  
Louis Sokoloff
Keyword(s):  
Estrous Cycle ◽  
Glucose Utilization ◽  
Brain Regions ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Normal Female ◽  
Female Rat ◽  
Males And Females ◽  
The Brain

The quantitative 2-[14C]deoxyglucose autoradiographic method was used to study the fluctuations of energy metabolism in discrete brain regions of female rats during the estrous cycle. A consistent though statistically nonsignificant cyclic variation in average glucose utilization of the brain as a whole was observed. Highest levels of glucose utilization occurred during proestrus and metestrus, whereas lower rates were found during estrus and diestrus. Statistically significant fluctuations were found specifically in the hypothalamus and in some limbic structures. Rates of glucose utilization in the female rat brain were compared with rates in normal male rats. Statistically significant differences between males and females at any stage of the estrous cycle were confined mainly to hypothalamic areas known to be involved in the control of sexual behavior. Glucose utilization in males and females was not significantly different in most other cerebral structures.

Melatonin administration entrains female rat activity rhythms in constant darkness but not in constant light

1988 ◽  
Vol 255 (2) ◽  
pp. R237-R242
Author(s):  
E. M. Thomas ◽  
S. M. Armstrong
Keyword(s):  
Estrous Cycle ◽  
Activity Rhythm ◽  
Onset Time ◽  
Circadian System ◽  
Female Rats ◽  
Male Rats ◽  
Constant Darkness ◽  
Female Rat ◽  
Continuous Darkness ◽  
Activity Rhythms

In female rats the luteinizing hormone (LH) is timed by the circadian system and is followed by a display of intense, estrogen-induced running behavior. This proestrous running on the night of ovulation can be used as a marker of the estrous cycle. Entrainment of the mammalian circadian system by exogenous melatonin (MT) has been demonstrated only in the activity rhythms of male rats. The present experiments were designed to study the effect of daily MT injections on activity rhythms and proestrous running of female rats in 1) continuous dim white light (LL) and 2) continuous darkness (DD). In LL, MT injections (50 micrograms/kg or 1 mg/kg) had no discernible effect on activity rhythms. In DD, four of the six MT-treated rats (100 micrograms/kg) entrained to the injection, and a fifth animal showed phase advances in its activity rhythm when onset of activity passed through injection time. The sixth animal was not injected with MT at activity onset time. None of the six control animals showed either effect. MT had no effect on the length of the estrous cycle. Thus MT injections can entrain circadian rhythms of activity and proestrous running in female rats in DD but not in LL.

scholarly journals The influence of 17β-estradiol on annexin 1 expression in the anterior pituitary of the female rat and in a folliculo-stellate cell line

2007 ◽  
Vol 192 (2) ◽  
pp. 429-442 ◽  
Author(s):  
Evelyn Davies ◽  
Selma Omer ◽  
John F Morris ◽  
Helen C Christian
Keyword(s):  
Cell Line ◽  
Estrous Cycle ◽  
Anterior Pituitary ◽  
Stellate Cell ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Annexin 1 ◽  
17Β Estradiol ◽  
Estrous Cycle Stage

Annexin 1 (ANXA1) is a Ca2+- and phospholipid-binding protein that plays an important role as a mediator of glucocorticoid action in the host-defence and neuroendocrine systems. Sex differences in hypothalamo–pituitary–adrenal (HPA) axis activity are well documented and a number of studies have demonstrated that gonadal steroids act as regulators of HPA activity. The aim of this study was to investigate the effect of ovariectomyand 17β-estradiol replacement, and estrous cycle stage, on anterior pituitary ANXA1 content. The amount of anterior pituitary ANXA1 determined by western blotting varied with estrous cycle stage with a peak at estrus declining to a trough at proestrus. Ovariectomy resulted in a significant (P<0.05) decrease in anterior pituitary ANXA1 content. Administration of 17β-estradiol (1 μg/100 g) significantly (P<0.01) increased anterior pituitary ANXA1 expression in the ovariectomized animals. In contrast, there was no change in pituitary ANXA1 content in response to 17β-estradiol in adrenalectomized and adrenalectomized/ovariectomized rats. Treatment of TtT/GF cells, a folliculo-stellate cell line, with 17β-estradiol (1.8–180 nM) increased ANXA1 mRNA expression and increased the amount of ANXA1 protein externalized in response to a dexamethasone stimulus. These results indicate that 17β-estradiol stimulates ANXA1 expression in the anterior pituitary and in vivo an adrenal factor contributes to the mechanism of action.

scholarly journals Atrazine-induced elevation or attenuation of the LH surge in the ovariectomized, estrogen-primed female rat: role of adrenal progesterone

Reproduction ◽  
2013 ◽  
Vol 146 (4) ◽  
pp. 305-314 ◽  
Author(s):  
Jerome M Goldman ◽  
Lori K Davis ◽  
Ashley S Murr ◽  
Ralph L Cooper
Keyword(s):  
Area Under The Curve ◽  
Neuronal Population ◽  
Female Rats ◽  
Female Rat ◽  
Single Treatment ◽  
Lh Surge ◽  
Multiple Exposures ◽  
Final Treatment ◽  
Herbicide Atrazine ◽  
Induced Changes

Multiple exposures to the herbicide atrazine (ATRZ) were shown to suppress the LH surge in both cycling female rats and those ovariectomized (OVX) and primed with estradiol (E2). A single ATRZ administration was found to induce a prompt and marked increase in progesterone (P4). As exogenous P4 is known to have a differential effect on the LH surge depending on its temporal relationship with the surge, it was hypothesized that a single treatment in an OVX, E2-primed rat would augment the surge, whereas several exposures would cause a decrease. Following four daily treatments with 100 mg/kg, LH surge was suppressed. In contrast, a single ATRZ exposure elevated the surge. Two treatments were without effect. The single administration caused a large increase in P4 at 30 and 60 min that was likely attributable to adrenal secretion. Four exposures also elevated P4 after the final treatment, although the duration of the increase was shortened. A single treatment with 0, 10, 30, and 100 mg/kg ATRZ showed similar elevations at the highest concentration in P4, the LH peak, and area under the curve (AUC), whereas four exposures reduced the AUC. An increase at 1 h in the expression of Kiss1 in the anteroventral periventricular nucleus suggests that this regional kisspeptin neuronal population has a role in the ATRZ augmentation of the surge. These data support the hypothesis that ATRZ-induced changes in adrenal P4 can either augment or attenuate the surge depending on the temporal proximity of exposure to the rise in LH.

scholarly journals In vitro effect of leptin on LH release by anterior pituitary glands from female rats at the time of spontaneous and steroid-induced LH surge

2001 ◽  
pp. 659-665 ◽  
Author(s):  
SN De Biasi ◽  
LI Apfelbaum ◽  
ME Apfelbaum
Keyword(s):  
Estrous Cycle ◽  
Anterior Pituitary ◽  
Female Rats ◽  
Female Rat ◽  
Lh Surge ◽  
Pituitary Glands ◽  
Lh Release ◽  
Vitro Effect ◽  
Stimulation Of

OBJECTIVE: The purpose of this work was to study the direct effect of leptin on LH release by anterior pituitary glands from female rats at the time of spontaneous and steroid-induced LH surge. METHODS: LH responsiveness to leptin by pituitaries from rats killed in the afternoon (1500 h) at different stages of the 4-day estrous cycle (diestrus-1: D1; diestrus-2: D2; proestrus; estrus), ovariectomized (OVX; 15 days post-castration) and ovariectomized steroid-primed (OVX-E(2)/Pg; pretreated with 5 microg estradiol and 1 mg progesterone), was evaluated in vitro. Hemi-adenohypophyses were incubated in the presence of synthetic murine leptin for 3 h. RESULTS: Addition of increasing concentrations of leptin (0.1-100 nmol/l) to the incubation medium of proestrus pituitaries produced a dose-related stimulation of LH release; the maximal increase to 315% of control was obtained with 10 nmol/l leptin. Leptin (10 nmol/l) enhanced LH release at all days of the estrous cycle, the greatest response occurring in proestrus (318%) and the lowest at D1 (123%). In order to evaluate the role of nitric oxide (NO) in the action of leptin on LH release, glands from proestrus rats were incubated in the presence of 10 nmol/l leptin with or without 0.3 mmol/l N(G)-monomethyl-l-arginine (NMMA), a competitive inhibitor of NO synthase (NOS). NMMA completely suppressed the stimulation of LH release induced by leptin. Leptin also stimulated LH release by pituitaries from OVX rats, and treatment with steroid hormones led to a marked increase in the response (OVX: 162% compared with OVX-E(2)/Pg: 263%; P<0.05). For comparative analysis, a similar experimental procedure was carried out using GnRH (10 nmol/l). Leptin acts at the pituitary level in a similar manner as GnRH, although with significantly lower potency. CONCLUSIONS: These results confirm and extend previous reports regarding a direct action of leptin at the pituitary level, stimulating LH release by anterior pituitaries from female rats at the time of spontaneous and steroid-induced LH surge. In the female rat pituitary this leptin action is controlled by gonadal steroids and mediated by NO.

Estrous cycle stage influences on neuronal responsiveness to repeated anxiogenic stress in female rats

2011 ◽  
Vol 225 (1) ◽  
pp. 334-340 ◽  
Author(s):  
Adam J. Devall ◽  
Julia M. Santos ◽  
Thelma A. Lovick
Keyword(s):  
Estrous Cycle ◽  
Female Rats ◽  
Estrous Cycle Stage

scholarly journals Differential Gonadotropin-Releasing Hormone (GnRH) and GnRH Receptor Messenger Ribonucleic Acid Expression Patterns in Different Tissues of the Female Rat across the Estrous Cycle

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3401-3408 ◽  
Author(s):  
Tamar D. Schirman-Hildesheim ◽  
Tzachi Bar ◽  
Nurit Ben-Aroya ◽  
Yitzhak Koch
Keyword(s):  
Estrous Cycle ◽  
Similar Pattern ◽  
Expression Patterns ◽  
Physiological Role ◽  
Gnrh Receptor ◽  
Mrna Levels ◽  
Female Rat ◽  
Messenger Ribonucleic Acid ◽  
Early Afternoon ◽  
Specific Regulation

Abstract GnRH, the main regulator of reproduction, is produced in a variety of tissues outside of the hypothalamus, its main site of synthesis and release. We aimed to determine whether GnRH produced in the female rat pituitary and ovaries is involved in the processes leading to ovulation. We studied the expression patterns of GnRH and GnRH receptor (GnRH-R) in the same animals throughout the estrous cycle using real-time PCR. Hypothalamic levels of GnRH mRNA were highest at 1700 h on proestrus, preceding the preovulatory LH surge. No significant changes in the level of hypothalamic GnRH-R mRNA were detected, although fluctuations during the day of proestrus are evident. High pituitary GnRH mRNA was detected during the day of estrus, in the morning of diestrus 1, and at noon on proestrus. Pituitary GnRH-R displayed a similar pattern of expression, except on estrus, when its mRNA levels declined. Ovarian GnRH mRNA levels increased in the morning of diestrus 1 and early afternoon of proestrus. Here, too, GnRH-R displayed a somewhat similar pattern of expression to that of its ligand. To the best of our knowledge, this is the first demonstration of a GnRH expression pattern in the pituitary and ovary of any species. The different timings of the GnRH peaks in the three tissues imply differential tissue-specific regulation. We believe that the GnRH produced in the anterior pituitary and ovary could play a physiological role in the preparation of these organs for the midcycle gonadotropin surge and ovulation, respectively, possibly via local GnRH-gonadotropin axes.

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