scholarly journals Estrogen Receptors Alpha and Beta Mediate Synaptic Transmission in the PFC and Hippocampus of Mice

2021 ◽  
Vol 22 (3) ◽  
pp. 1485
Author(s):  
Mingyue Zhang ◽  
Hannah Weiland ◽  
Michael Schöfbänker ◽  
Weiqi Zhang
Keyword(s):  
Estrogen Receptor ◽  
Synaptic Transmission ◽  
Estrogen Receptors ◽  
Hippocampal Slices ◽  
Physiological Role ◽  
Glutamatergic Transmission ◽  
Postsynaptic Currents ◽  
Specific Manner ◽  
The Brain

Distinct from ovarian estradiol, the steroid hormone 17ß-estradiol (E2) is produced in the brain and is involved in numerous functions, particularly acting as a neurosteroid. However, the physiological role of E2 and the mechanism of its effects are not well known. In hippocampal slices, 17ß-estradiol has been found to cause a modest increase in fast glutamatergic transmission; because some of these effects are rapid and acute, they might be mediated by membrane-associated receptors via nongenomic action. Moreover, activation of membrane estrogen receptors can rapidly modulate neuron function in a sex-specific manner. To further investigate the neurological role of E2, we examined the effect of E2, as an estrogen receptor (ER) agonist, on synaptic transmission in slices of the prefrontal cortex (PFC) and hippocampus in both male and female mice. Whole-cell recordings of spontaneous excitatory postsynaptic currents (sEPSC) in the PFC showed that E2 acts as a neuromodulator in glutamatergic transmission in the PFC in both sexes, but often in a cell-specific manner. The sEPSC amplitude and/or frequency responded to E2 in three ways, namely by significantly increasing, decreasing or having no response. Additional experiments using an agonist selective for ERß, diarylpropionitrile (DPN) showed that in males the sEPSC and spontaneous inhibitory postsynaptic currents sIPSC responses were similar to their E2 responses, but in females the estrogen receptor ß (ERß) agonist DPN did not influence excitatory transmission in the PFC. In contrast, in the hippocampus of both sexes E2 potentiated the gluatmatergic synaptic transmission in a subset of hippocampal cells. These data indicate that activation of E2 targeting probably a estrogen subtypes or different downstream signaling affect synaptic transmission in the brain PFC and hippocampus between males versus females mice.

scholarly journals Az ösztrogénmetabolom biológiai és klinikai jelentősége lokális folyamatokban

2017 ◽  
Vol 158 (24) ◽  
pp. 929-937
Author(s):  
Krisztián Kovács ◽  
Barna Vásárhelyi ◽  
Katalin Mészáros ◽  
Attila Patócs ◽  
Gellért Karvaly
Keyword(s):  
Biological Activity ◽  
Clinical Significance ◽  
Physiological Role ◽  
Tissue Homeostasis ◽  
Diagnostic Significance ◽  
Peripheral Tissues ◽  
Breakdown Process ◽  
Specific Manner ◽  
Related Compounds

Abstract: Considerable knowledge has been gathered on the physiological role of estrogens. However, fairly little information is available on the role of compounds produced in the breakdown process of estrone and estradiol wich may play a role in various diseases associated with estrogen impact. To date, approximately 15 extragonadal estrogen-related compounds have been identified. These metabolites may exert protective, or, instead, pro-inflammatory and/or pro-oncogenic activity in a tissue-specific manner. Systemic and local estrogen metabolite levels are not necesserily correlated, which may promote the diagnostic significance of the locally produced estrogen metabolites in the future. The aim of the present study is a bibliographic review of the extragonadal metabolome in peripheral tissues, and to highlight the role of the peripheral tissue homeostasis of estrogens as well as the non-hormonal biological activity and clinical significance of the estrogen metabolome. Orv Hetil. 2017; 158(24): 929–937.

scholarly journals Influences of Morphine on the Spontaneous and Evoked Excitatory Postsynaptic Currents in Lateral Amygdala of Rats

2016 ◽  
pp. 165-169 ◽  
Author(s):  
J.-J. ZHANG ◽  
X.-D. LIU ◽  
L.-C. YU
Keyword(s):  
Synaptic Transmission ◽  
Excitatory Synaptic Transmission ◽  
Morphine Treatment ◽  
Lateral Amygdala ◽  
Excitatory Postsynaptic Currents ◽  
Postsynaptic Currents ◽  
Whole Cell Patch Clamp ◽  
The Central Nervous System ◽  
Underlying Mechanisms

Acute morphine exposure induces antinociceptive activity, but the underlying mechanisms in the central nervous system are unclear. Using whole-cell patch clamp recordings, we explore the role of morphine in the modulation of excitatory synaptic transmission in lateral amygdala neurons of rats. The results demonstrate that perfusion of 10 μM of morphine to the lateral amygdala inhibits the discharge frequency significantly. We further find that there are no significant influences of morphine on the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs). Interestingly, morphine shows no marked influence on the evoked excitatory postsynaptic currents (eEPSCs) in the lateral amygdala neurons. These results indicate that acute morphine treatment plays an important role in the modulation on the excitatory synaptic transmission in lateral amygdala neurons of rats.

scholarly journals Adenosine A1 receptor-mediated protection of mouse hippocampal synaptic transmission against oxygen and/or glucose deprivation: a comparative study

2019 ◽  
Vol 122 (2) ◽  
pp. 721-728 ◽  
Author(s):  
Masahito Kawamura ◽  
David N. Ruskin ◽  
Susan A. Masino
Keyword(s):  
Synaptic Transmission ◽  
Hippocampal Slices ◽  
Glucose Deprivation ◽  
Acute Response ◽  
Recording Conditions ◽  
Receptor Inactivation ◽  
Acute Hippocampal Slices ◽  
Metabolic Stresses ◽  
The Impact

Adenosine receptors are widely expressed in the brain, and adenosine is a key bioactive substance for neuroprotection. In this article, we clarify systematically the role of adenosine A1 receptors during a range of timescales and conditions when a significant amount of adenosine is released. Using acute hippocampal slices obtained from mice that were wild type or null mutant for the adenosine A1 receptor, we quantified and characterized the impact of varying durations of experimental ischemia, hypoxia, and hypoglycemia on synaptic transmission in the CA1 subregion. In normal tissue, these three stressors rapidly and markedly reduced synaptic transmission, and only treatment of sufficient duration led to incomplete recovery. In contrast, inactivation of adenosine A1 receptors delayed and/or lessened the reduction in synaptic transmission during all three stressors and reduced the magnitude of the recovery significantly. We reproduced the responses to hypoxia and hypoglycemia by applying an adenosine A1 receptor antagonist, validating the clear effects of genetic receptor inactivation on synaptic transmission. We found activation of adenosine A1 receptor inhibited hippocampal synaptic transmission during the acute phase of ischemia, hypoxia, or hypoglycemia and caused the recovery from synaptic impairment after these three stressors using genetic mutant. These studies quantify the neuroprotective role of the adenosine A1 receptor during a variety of metabolic stresses within the same recording system. NEW & NOTEWORTHY Deprivation of oxygen and/or glucose causes a rapid adenosine A1 receptor-mediated decrease in synaptic transmission in mouse hippocampus. We quantified adenosine A1 receptor-mediated inhibition during and synaptic recovery after ischemia, hypoxia, and hypoglycemia of varying durations using a genetic mutant and confirmed these findings using pharmacology. Overall, using the same recording conditions, we found the acute response and the neuroprotective ability of the adenosine A1 receptor depended on the type and duration of deprivation event.

Membrane-Initiated Estradiol Signaling in the Central Nervous System

2019 ◽  
Author(s):  
Paul E. Micevych ◽  
Melinda A. Mittelman-Smith
Keyword(s):  
Nervous System ◽  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
G Protein ◽  
Nuclear Receptors ◽  
Signaling Cascades ◽  
Estrogen Signaling ◽  
Female Reproduction ◽  
Brain Physiology ◽  
The Brain

In the last two decades of the 20th century, key findings in the field of estrogen signaling completely changed our understanding of hormones: first, steroidogenesis was demonstrated in the CNS; second, a vast majority of cells in the nervous system were shown to have estrogen receptors; third, a second nuclear estrogen receptor (ERß) was cloned; and finally, “nuclear” receptors were shown to be present and functional in the cell membrane. Shortly thereafter, even more membrane estrogen receptors were discovered. Steroids (estrogens, in particular) began to be considered as neurotransmitters and their receptors were tethered to G protein-coupled receptor signaling cascades. In some parts of the brain, levels of steroids appeared to be independent of those found in the circulation and yet, circulating steroids had profound actions on the brain physiology. In this review, we discuss the interaction of peripheral and central estrogen action in the context of female reproduction—one of the best-studied aspects of steroid action. In addition to reviewing the evidence for steroidogenesis in the hypothalamus, we review membrane-localized nuclear receptors coupling to G protein-signaling cascades and the downstream physiological consequences for reproduction. We will also introduce newer work that demonstrates cell signaling for a common splice variant of estrogen receptor-α (ERα), and membrane action of neuroprogesterone in regulating estrogen positive feedback.

Enhancement of Whole Cell Synaptic Currents by Low Osmolarity and by Low [NaCl] in Rat Hippocampal Slices

1997 ◽  
Vol 77 (5) ◽  
pp. 2349-2359 ◽  
Author(s):  
Rong Huang ◽  
Daniel F. Bossut ◽  
George G. Somjen
Keyword(s):  
Synaptic Transmission ◽  
Time Constant ◽  
Hippocampal Slices ◽  
Input Resistance ◽  
Tissue Slices ◽  
Synaptic Currents ◽  
Whole Cell ◽  
Input Capacitance ◽  
Postsynaptic Currents ◽  
Inward Currents

Huang, Rong, Daniel F. Bossut, and George G. Somjen. Enhancement of whole cell synaptic currents by low osmolarity and by low [NaCl] in rat hippocampal slices. J. Neurophysiol. 77: 2349–2359, 1997. We recorded whole cell currents of patch-clamped neurons in stratum pyramidale of CA1 region of rat hippocampal tissue slices. Synaptic currents were evoked by orthodromic stimulation while holding potential of the neuron was varied from hyperpolarized to depolarized levels. Extracellular osmolarity (πo) was lowered by superfusion with artificial cerebrospinal fluid in which NaCl concentration ([NaCl]) was reduced. The effect of low extracellular NaCl was tested in additional trials in which NaCl was substituted by isosmolar fructose. Both lowering of πo and isosmotic lowering of extracellular [NaCl] ([NaCl]o) caused reversible increase of excitatory postsynaptic currents. The effect of lowering πo was concentration dependent, and it was significantly stronger than the effect of equivalent isosmotic lowering of [NaCl]o. Inhibitory postsynaptic currents also increased in many but not in all cases. Lowering of πo caused a prolongation of the time constant of relaxation of the capacitive charging current induced by small hyperpolarizing voltage steps. A virtual input capacitance, calculated by dividing this time constant by the input resistance, increased during hypotonic exposure. Isosmotic lowering of [NaCl]o had no effect on time constant or input capacitance. Depolarizing voltage commands evoked spikelike inward currents presumably representing Na+-dependent action potentials generated outside the voltage-clamped region of the cell. These current spikes became smaller in low πo and in low [NaCl]o. Broader, voltage-dependent, presumably Ca2+-mediated inward currents became more prominent during hypotonic exposure. We conclude that lowering of [NaCl]o causes enhancement of excitatory synaptic transmission. Transmission may be facilitated by the uptake of Ca2+ into presynaptic terminals as well as into postsynaptic target neurons, induced by the low [NaCl]o. Lowering of πo enhances synaptic transmission more than does a corresponding isosmotic lowering of [NaCl]. The excess increase recorded from the cell soma in low πo may in part be due to changing electrotonic length caused by the swelling of dendrites.

scholarly journals Activation of Southern White Rhinoceros (Ceratotherium simum simum) Estrogen Receptors by Phytoestrogens: Potential Role in the Reproductive Failure of Captive-Born Females?

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1444-1452 ◽  
Author(s):  
Christopher Tubbs ◽  
Phillip Hartig ◽  
Mary Cardon ◽  
Nicole Varga ◽  
Matthew Milnes
Keyword(s):  
Estrogen Receptors ◽  
Potential Role ◽  
Physiological Role ◽  
Reproductive Failure ◽  
Vertebrate Species ◽  
Ceratotherium Simum ◽  
White Rhinoceros ◽  
Southern White Rhinoceros ◽  
Ceratotherium Simum Simum

The captive southern white rhinoceros (SWR; Ceratotherium simum simum) population serves as an important genetic reservoir critical to the conservation of this vulnerable species. Unfortunately, captive populations are declining due to the poor reproductive success of captive-born females. Captive female SWR exhibit reproductive problems suggested to result from continual ovarian follicular activity and prolonged exposure to endogenous estrogen. However, we investigated the potential role of exogenous dietary phytoestrogens in the reproductive failure of SWR by cloning and characterizing in vitro phytoestrogen binding and activation of recombinant SWR estrogen receptors (ESR). We compared those characteristics with recombinant greater one-horned rhinoceros (GOHR; Rhinoceros unicornis) ESR, a species that receives similar captive diets yet reproduces relatively well. Our results indicate that phytoestrogens bind rhino ESR in a manner similar to other vertebrate species, but there are no differences found in phytoestrogen binding affinity of SWR ESR compared with GOHR ESR. However, species-specific differences in ESR activation by phytoestrogens were detected. The phytoestrogen coumestrol stimulated greater maximal activation of SWR ESR1 than GOHR ESR1. SWR ESR2 were also more sensitive to phytoestrogens and were activated to a greater extent by both coumestrol and daidzein. The concentrations in which significant differences in ESR activation occurred (10−7 to 10−5m) are consistent with circulating concentrations measured in other vertebrate species. Taken together, these findings suggest that phytoestrogens potentially pose a risk to the reproductive health of captive SWR. However, additional studies are needed to further clarify the physiological role of dietary phytoestrogens in the reduced fertility of this species.

scholarly journals Anthocyanins Activate Membrane Estrogen Receptors With Nanomolar Potencies to Elicit a Nongenomic Vascular Response Via NO Production

2021 ◽  
Author(s):  
Camila Calfío ◽  
Francisca Donoso ◽  
J. Pablo Huidobro‐Toro
Keyword(s):  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
Rapid Onset ◽  
No Production ◽  
Vascular Response ◽  
Selective Antagonists ◽  
Joint Application ◽  
Before And After ◽  
Estrogen Receptor Activity

Background The vascular pharmacodynamics of anthocyanins is only partially understood. To examine whether the anthocyanin‐induced vasorelaxation is related to membrane estrogen receptor activity, the role of ERα or GPER antagonism was ascertained on anthocyanins or 17‐β estradiol‐(E2) induced vasodilatations and NO production. Methods and Results The rat arterial mesenteric bed was perfused with either anthocyanins or corresponding 3‐O‐glycosides, or E2, to examine rapid concentration‐dependent vasorelaxations. The luminally accessible fraction of NO in mesenteric perfusates before and after anthocyanins or E2 administration was quantified. Likewise, NO‐DAF signal detected NO production in primary endothelial cells cultures incubated with anthocyanins or E2 in the absence and presence of ERα (ICI 182,780) or GPER (G‐36) selective antagonists. Anthocyanins or corresponding glycosides elicited, within minutes, vasodilation with nanomolar potencies; half maximal anthocyanin response reached 50% to 60% efficacy, in contrast to acetylcholine. The vasorelaxation is of rapid onset and exclusively endothelium‐dependent; NOS inhibition annulled the vasorelaxation. The delphinidin vascular response was not modified by 100 nmol/L atropine but significantly attenuated by joint application of ICI plus G‐36 (52±4.6 versus 8.5±1.5%), revealing the role of membrane estrogen receptors. Moreover, the anthocyanin or E2‐induced NO production was antagonized up to 70% by these antagonists. NO‐DAF signal elicited by anthocyanins was annulled by NOS inhibition or by ICI plus G‐36 addition. Conclusions The biomedical effect of anthocyanins or 3‐O‐glycosylates derivatives contained in naturally purple‐colored foods or berries is due to increased NO production, and not to the phytochemical's antioxidant potential, highlighting the nutraceutical role of natural products in cardiovascular diseases.

scholarly journals Molecular mechanisms of estrogen receptor β-induced apoptosis and autophagy in tumors: implication for treating osteosarcoma

2019 ◽  
Vol 47 (10) ◽  
pp. 4644-4655
Author(s):  
Zheng-ming Yang ◽  
Min-fei Yang ◽  
Wei Yu ◽  
Hui-min Tao
Keyword(s):  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Critical Role ◽  
Osteosarcoma Cells ◽  
Proliferation And Metastasis ◽  
Induced Apoptosis

The estrogen receptors α (ERα) and β (ERβ) are located in the nucleus and bind to estrogen to initiate transcription of estrogen-responsive genes. In a variety of tumor cells, ERβ has been shown to be a tumor suppressor. In particular, ERβ has anti-proliferative effects in osteosarcoma cells. Additionally, ERβ has been proven to regulate the apoptosis-related molecules IAP, BAX, caspase-3, and PARP, and to act on the NF-κB/BCL-2 pathway to induce apoptosis in tumors. Moreover, ERβ can regulate the expression of the autophagy associated markers LC3-I/LC-3II and p62 and induce autophagy in tumors by inhibiting the PI3K/AKT/mTOR pathway and activating the AMPK pathway. Here, we review the molecular mechanisms by which ERβ induces apoptosis and autophagy in a variety of tumors to further delineate more specific molecular mechanisms underlying osteosarcoma tumorigenesis and pathogenesis. Considering the broad involvement of ERβ in apoptosis, autophagy, and their interaction, it is plausible that the critical role of ERβ in inhibiting the proliferation and metastasis of osteosarcoma cells is closely related to its regulation of apoptosis and autophagy.

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