scholarly journals Estradiol-Induced Synaptic Remodeling of Tyrosine Hydroxylase Immunopositive Neurons in the Rat Arcuate Nucleus

Endocrinology ◽  
2008 ◽  
Vol 149 (8) ◽  
pp. 4137-4141 ◽  
Author(s):  
Eszter Csakvari ◽  
Anita Kurunczi ◽  
Zsofia Hoyk ◽  
Andrea Gyenes ◽  
Frederick Naftolin ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Arcuate Nucleus ◽  
Neuronal Firing ◽  
Female Rats ◽  
Synaptic Connectivity ◽  
Numerical Density ◽  
Synaptic Remodeling ◽  
Male And Female Rats ◽  
17Β Estradiol ◽  
Arcuate Neurons

Gonadal steroids induce synaptic plasticity in several areas of the adult nervous system. In the arcuate nucleus of adult female rats, 17β-estradiol triggers synaptic remodeling, resulting in a decrease in the number of inhibitory synaptic inputs, an increase in the number of excitatory synapses, and an enhancement of the frequency of neuronal firing. In the present paper, we studied the specificity of hormonal effects by determining the changes in synaptic connectivity of tyrosine hydroxylase (TH) immunoreactive (IR) neurons in the arcuate nucleus. We combined pre-embedding TH and post-embedding γ-aminobutyric acid (GABA) immunostaining, and performed unbiased stereological measurements in gonadectomized and 17β-estradiol-treated rats. We conclude that the synaptic connectivity of the TH-IR neurons is different from the other, nonlabeled population, and the response to estradiol is not uniform. TH-IR (dopaminergic) arcuate neurons of both male and female rats have more GABAergic (inhibitory) axosomatic inputs than the nondopaminergic population. Our study shows that the effect of 17β-estradiol is sex and cell specific in the sense that not all arcuate neurons are affected by the structural synaptic remodeling. In ovariectomized females hormone treatment decreased the numerical density of GABAergic axosomatic synapses on TH-IR, but not on nondopaminergic, neurons, whereas in orchidectomized males, 17β-estradiol treatment increased inhibitory synapses onto nondopaminergic neurons but did not affect the number of inhibitory terminals onto TH-IR neurons. The hormone-induced plastic changes in synaptic connectivity of TH-IR neurons may serve as the morphological basis for the cyclical regulation of the anterior pituitary.

scholarly journals Estrogenic-dependent glutamatergic neurotransmission from kisspeptin neurons governs feeding circuits in females

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Jian Qiu ◽  
Heidi M Rivera ◽  
Martha A Bosch ◽  
Stephanie L Padilla ◽  
Todd L Stincic ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Arcuate Nucleus ◽  
Neuronal Excitability ◽  
Glutamate Release ◽  
Metabotropic Receptors ◽  
Hypothalamic Arcuate Nucleus ◽  
17Β Estradiol ◽  
Arcuate Neurons ◽  
Feeding Circuits

The neuropeptides tachykinin2 (Tac2) and kisspeptin (Kiss1) in hypothalamic arcuate nucleus Kiss1 (Kiss1ARH) neurons are essential for pulsatile release of GnRH and reproduction. Since 17β-estradiol (E2) decreases Kiss1 and Tac2 mRNA expression in Kiss1ARH neurons, the role of Kiss1ARH neurons during E2-driven anorexigenic states and their coordination of POMC and NPY/AgRP feeding circuits have been largely ignored. Presently, we show that E2 augmented the excitability of Kiss1ARH neurons by amplifying Cacna1g, Hcn1 and Hcn2 mRNA expression and T-type calcium and h-currents. E2 increased Slc17a6 mRNA expression and glutamatergic synaptic input to arcuate neurons, which excited POMC and inhibited NPY/AgRP neurons via metabotropic receptors. Deleting Slc17a6 in Kiss1 neurons eliminated glutamate release and led to conditioned place preference for sucrose in E2-treated KO female mice. Therefore, the E2-driven increase in Kiss1 neuronal excitability and glutamate neurotransmission may play a key role in governing the motivational drive for palatable food in females.

Birthdates of the Tyrosine Hydroxylase Immunoreactive Neurons in the Hypothalamus of Male and Female Rats

1996 ◽  
Vol 64 (6) ◽  
pp. 405-411 ◽  
Author(s):  
Irina S. Balan ◽  
Michael V. Ugrumov ◽  
Nina A. Borisova ◽  
André Calas ◽  
Christof Pilgrim ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

scholarly journals Genistein during Development Alters Differentially the Expression of POMC in Male and Female Rats

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 293
Author(s):  
Jose Manuel Fernandez-Garcia ◽  
Beatriz Carrillo ◽  
Patricia Tezanos ◽  
Paloma Collado ◽  
Helena Pinos
Keyword(s):  
Body Weight ◽  
Sex Differences ◽  
Energy Metabolism ◽  
Arcuate Nucleus ◽  
Caloric Intake ◽  
The Body ◽  
Female Rats ◽  
Male And Female ◽  
Dorsomedial Hypothalamus ◽  
Male And Female Rats

Phytoestrogens are considered beneficial for health, but some studies have shown that they may cause adverse effects. This study investigated the effects of genistein administration during the second week of life on energy metabolism and on the circuits regulating food intake. Two different genistein doses, 10 or 50 µg/g, were administered to male and female rats from postnatal day (P) 6 to P13. Physiological parameters, such as body weight and caloric intake, were then analyzed at P90. Moreover, proopiomelanocortin (POMC) expression in the arcuate nucleus (Arc) and orexin expression in the dorsomedial hypothalamus (DMH), perifornical area (PF) and lateral hypothalamus (LH) were studied. Our results showed a delay in the emergence of sex differences in the body weight in the groups with higher genistein doses. Furthermore, a significant decrease in the number of POMC-immunoreactive (POMC-ir) cells in the Arc in the two groups of females treated with genistein was observed. In contrast, no alteration in orexin expression was detected in any of the structures analyzed in either males or females. In conclusion, genistein can modulate estradiol’s programming actions on the hypothalamic feeding circuits differentially in male and female rats during development.

scholarly journals Oxytocin has sex-specific effects on social behaviour and hypothalamic oxytocin immunoreactive cells but not hippocampal neurogenesis in adult rats

2019 ◽  
Author(s):  
Paula Duarte-Guterman ◽  
Stephanie E. Lieblich ◽  
Wansu Qiu ◽  
Jared E.J. Splinter ◽  
Kimberly A. Go ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Body Mass ◽  
Hippocampal Neurogenesis ◽  
Female Rats ◽  
Brain Barrier ◽  
Social Investigation ◽  
Male And Female ◽  
Specific Effects ◽  
Male And Female Rats ◽  
17Β Estradiol

AbstractOxytocin regulates social behaviours, pair bonding and hippocampal neurogenesis but most studies have used adult males. Our study investigated the effects of oxytocin on social investigation and adult hippocampal neurogenesis in male and female rats. Oxytocin has poor penetration of the blood-brain barrier, therefore we tested a nanoparticle drug, TRIOZANTM (Ovensa Inc.), which permits greater blood-brain-barrier penetration. Adult male and female rats were injected daily (i.p.) for 10 days with either: oxytocin in PBS (0.5 or 1.0 mg/kg), oxytocin in TRIOZANTM (0.5 or 1.0 mg/kg), or vehicle (PBS) and tested for social investigation. Oxytocin decreased body mass and increased social investigation and number of oxytocin-immunoreactive cells in the supraoptic nucleus (SON) of the hypothalamus in male rats only. In both sexes, oxytocin decreased the number of immature neurons (doublecortin+ cells) in the ventral hippocampus and reduced plasma 17β-estradiol levels in a dose- and delivery-dependent way. Oxytocin in TRIOZANTM reduced sedation observed post-injection and increased some central effects (oxytocin levels in the hypothalamus and ventral hippocampus neurogenesis) relative to oxytocin in PBS indicating that the nanoparticle may be used as an alternative brain delivery system. We showed that oxytocin has sex-specific effects on social investigation, body mass, sedation, and the oxytocin system. In contrast, similar effects were observed in both sexes in neurogenesis and plasma 17β-estradiol. Our work suggests that sex differences in oxytocin regulation of brain endpoints is region-specific (hypothalamus versus hippocampus) and that oxytocin does not promote social investigation in females.

Qualification of a 17β-estradiol (E2) Assay in Sprague Dawley Rat Serum

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S85-S86
Author(s):  
J A Martin ◽  
J Figueiredo ◽  
L Wang
Keyword(s):  
Hemoglobin Concentration ◽  
Female Rats ◽  
Sprague Dawley ◽  
Serum Samples ◽  
Rat Serum ◽  
Data Set ◽  
A Value ◽  
Male And Female Rats ◽  
17Β Estradiol ◽  
Assay Precision

Abstract Introduction/Objective Significant technical issues are associated with methods used for the measurement of estradiol.The objective of this study was to qualify an electrochemiluminescent (ECL) assay for the quantification of 17β-estradiol (E2) in rat serum. Hemolysis has been identified as a factor that interferes with accurate measurement.The impact of hemolysis was also assessed. Methods Approximately 1.0 mL of whole blood was collected from male and female rats into separate red top tubes and processed to serum. The LoQ for E2 was evaluated by analyzing the low calibrator or at least 6 serum samples diluted to produce a value at the low end of the reportable range 8 times in the same run.The mean, standard deviation, and %CV were calculated for each sample.The data set was analyzed by plotting the data and determining the concentration at the intersection of the precision profile curve. Linearity of dilution was performed using commercially available calibration verification material and E2 stripped rat serum.The correlation coefficient, the slope, and the % Nominal were calculated. Intra assay precision was evaluated by analyzing 8 consecutive times in a single run one rat serum sample that was not diluted or spiked. This analysis was performed during the evaluation of the LoQ.The mean, SD and %CV were calculated. The interference of hemolysis with the E2 assay was tested by analyzing at least 5 rat serum samples/pools spiked with hemolyzed rat serum at different hemoglobin concentrations.The %RE was calculated. Results The LoQ assays were acceptable. For all samples tested, the % CV was less than or equal to 25%.The LoQ was verified to be 8.50 pg/mL. The %CV was 15.6%. For samples with estradiol concentrations below the LoQ, a value of 4.25 pg/ml was reported. Linearity of dilution for E2 was acceptable.The correlation coefficients were greater than or equal to 0.9000, the slopes were between 0.7500 and 1.2500, and the % nominals for each level were between 75-125%. The intra-assay precision was considered acceptable with a %CV of 8.6%. There was no hemolysis interference in the assay when samples were spiked with hemoglobin concentrations of up to 70 mg/dL, based on the %RE of less than or equal to 25% of non-hemolyzed samples. Conclusion Qualification of the ECL method, demonstrates the assay is suitable for the determination of E2 in serum samples from rats and absence of hemolysis interference up to 70 mg/dL of hemoglobin concentration.

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