scholarly journals Dendritic osmosensors modulate activity-induced calcium influx in oxytocinergic magnocellular neurons of the mouse PVN

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Wanhui Sheng ◽  
Scott W Harden ◽  
Yalun Tan ◽  
Eric G Krause ◽  
Charles J Frazier
Keyword(s):  
Ion Channels ◽  
Paraventricular Nucleus ◽  
Calcium Influx ◽  
Optical Recording ◽  
Magnocellular Neurons ◽  
Axon Terminals ◽  
Dendritic Membrane ◽  
Oxytocin Release ◽  
The Relationship ◽  
Existing Data

Hypothalamic oxytocinergic magnocellular neurons have a fascinating ability to release peptide from both their axon terminals and from their dendrites. Existing data indicates that the relationship between somatic activity and dendritic release is not constant, but the mechanisms through which this relationship can be modulated are not completely understood. Here we use a combination of electrical and optical recording techniques to quantify activity-induced calcium influx in proximal vs. distal dendrites of oxytocinergic magnocellular neurons located in the paraventricular nucleus of the hypothalamus (OT-MCNs). Results reveal that the dendrites of OT-MCNs are weak conductors of somatic voltage changes, however activity-induced dendritic calcium influx can be robustly regulated by both osmosensitive and non-osmosensitive ion channels located along the dendritic membrane. Overall, this study reveals that dendritic conductivity is a dynamic and endogenously regulated feature of OT-MCNs that is likely to have substantial functional impact on central oxytocin release.

scholarly journals Dendritic membrane resistance modulates activity-induced Ca2+ influx in oxytocinergic magnocellular neurons of mouse PVN

2021 ◽  
Author(s):  
Wanhui Sheng ◽  
Scott W. Harden ◽  
Yalun Tan ◽  
Eric G. Krause ◽  
Charles J. Frazier
Keyword(s):  
Paraventricular Nucleus ◽  
Calcium Influx ◽  
Membrane Resistance ◽  
Optical Recording ◽  
Magnocellular Neurons ◽  
Axon Terminals ◽  
Dendritic Membrane ◽  
Oxytocin Release ◽  
Activity Dependent ◽  
Existing Data

ABSTRACTHypothalamic oxytocinergic magnocellular neurons have a fascinating ability to release peptide from both their axon terminals and from their dendrites. Existing data indicates there is a flexible relationship between somatic activity and dendritic release, but the mechanisms governing this relationship are not completely understood. Here we use a combination of electrical and optical recording techniques to quantify activity-dependent calcium influx in proximal vs. distal dendrites of oxytocinergic magnocellular neurons located in the paraventricular nucleus of the hypothalamus (OT-MCNs). Results reveal that the dendrites of OT-MCNs are weak conductors of somatic voltage changes, and yet activity-induced dendritic calcium influx can be robustly regulated by a diverse set of stimuli that open or close ionophores located along the dendritic membrane. Overall, this study reveals that dendritic membrane resistance is a dynamic and endogenously regulated feature of OT-MCNs that is likely to have substantial functional impact on central oxytocin release.IMPACT STATEMENTActivity-induced dendritic calcium influx in oxytocinergic magnocellular neurons can be robustly modulated by a highly diverse set of stimuli acting on distinct types of ionophores expressed along the dendritic membrane.

scholarly journals Does Respect Foster Tolerance? (Re)analyzing and Synthesizing Data From a Large Research Project Using Meta-Analytic Techniques

2021 ◽  
pp. 014616722110244
Author(s):  
Steffen Zitzmann ◽  
Lukas Loreth ◽  
Klaus Michael Reininger ◽  
Bernd Simon
Keyword(s):  
Regression Coefficient ◽  
Theory Development ◽  
High Status ◽  
Social Psychological ◽  
Way Of Life ◽  
Research Project ◽  
The Social ◽  
The Relationship ◽  
Large Research ◽  
Existing Data

Our own prior research has demonstrated that respect for disapproved others predicts and might foster tolerance toward them. This means that without giving up their disapproval of others’ way of life, people can tolerate others when they respect them as equals (outgroup respect–tolerance hypothesis). Still, there was considerable variation in the study features. Moreover, the studies are part of a larger research project that affords many additional tests of our hypothesis. To achieve integration along with a more robust understanding of the relation between respect and tolerance, we (re)analyzed all existing data from this project, and we synthesized the results with the help of meta-analytic techniques. The average standardized regression coefficient, which describes the relationship between respect and tolerance, was 0.25 (95% confidence interval [CI] = [0.16, 0.34]). In addition to this overall confirmation of our hypothesis, the size of this coefficient varied with a number of variables. It was larger for numerical majorities than for minorities, smaller for high-status than for low-status groups, and larger for religious than for life-style groups. These findings should inspire further theory development and spur growth in the social-psychological literature on tolerance.

scholarly journals Increased oxytocin release precedes hyponatremia after pituitary surgery

Pituitary ◽  
2021 ◽  
Author(s):  
Paul Eugène Constanthin ◽  
Nathalie Isidor ◽  
Sophie de Seigneux ◽  
Shahan Momjian
Keyword(s):  
Transsphenoidal Surgery ◽  
Pituitary Surgery ◽  
Sodium Balance ◽  
Posterior Pituitary ◽  
Axon Terminals ◽  
Early Marker ◽  
Inappropriate Secretion ◽  
Oxytocin Release ◽  
Transsphenoidal Pituitary Surgery ◽  
First Time

Abstract Purpose The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a well-known complication of transsphenoidal pituitary surgery, related to inappropriate secretion of arginine vasopressin (AVP). Its diagnosis is based on hyponatremia, with a peak of occurrence around day 7 after surgery and, to date, no early marker has been reported. In particular, copeptin levels are not predictive of hyponatremia in this case. Oxytocin (OXT) is secreted into the peripheral blood by axon terminals adjacent to those of AVP neurons in the posterior pituitary. Besides its role in childbirth and lactation, recent evidences suggested a role for OXT in sodium balance. The contribution of this hormone in the dysnatremias observed after pituitary surgery has however never been investigated. Methods We analyzed the urinary output of OXT in patients subjected to transsphenoidal pituitary surgery. Results While OXT excretion remained stable in patients who presented a normonatremic postoperative course, patients who were later diagnosed with SIADH-related hyponatremia presented with a significantly increased urinary secretion of OXT 4 days after surgery. Conclusion Taken together, these results show for the first time that urinary OXT output remains normally stable after transsphenoidal pituitary surgery. OXT excretion however becomes abnormally high on or around 4 days after surgery in patients later developing hyponatremia, suggesting that this abnormal dynamics of OXT secretion might serve as an early marker for transsphenoidal surgery-related hyponatremia attributed to SIADH.

scholarly journals Meta-Analysis—Correlation between Spiral Ganglion Cell Counts and Speech Perception with a Cochlear Implant

2021 ◽  
Vol 11 (2) ◽  
pp. 220-226
Author(s):  
Yew-Song Cheng ◽  
Mario A. Svirsky
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Ganglion Cells ◽  
Meta Analysis ◽  
Spiral Ganglion ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Temporal Bones ◽  
The Relationship ◽  
Existing Data

The presence of spiral ganglion cells (SGCs) is widely accepted to be a prerequisite for successful speech perception with a cochlear implant (CI), because SGCs provide the only known conduit between the implant electrode and the central auditory system. By extension, it has been hypothesized that the number of SGCs might be an important factor in CI outcomes. An impressive body of work has been published on findings from the laborious process of collecting temporal bones from CI users and counting the number of SGCs to correlate those numbers with speech perception scores, but the findings thus far have been conflicting. We performed a meta-analysis of all published studies with the hope that combining existing data may help us reach a more definitive conclusion about the relationship between SGC count and speech perception scores in adults.

Abstract 12: Feasibility of Monitoring Covid-19 Related Stroke Patients Across a 14 Hospital Stroke System of Care

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Howard J Rho ◽  
Navdeep S Sangha
Keyword(s):  
Stroke Care ◽  
Stroke Patients ◽  
Specific Data ◽  
Related Data ◽  
Disease States ◽  
Hospital Systems ◽  
Pandemic Response ◽  
Relationship Of ◽  
The Relationship ◽  
Existing Data

Background: Identifying and tracking COVID-19 related data has been crucial to the pandemic response. Most hospital systems have created internal tracking databases specific to COVID-19 but separated from other disease specific data pools. Traditional methods for tracking and trending novel and specific data such as COVID-19 related strokes may require personnel with highly technical skills to abstract the data. We aimed to create a COVID-19 stroke dashboard which would easily auto-abstract and update data. Methods: A simple monitoring system was designed using PowerBI™ and Microsoft Suite™ products that model existing data sources without using other IT resources. Existing data queries from various sources were modeled into one report and the resulting data model was used to track and trend incidence of COVID-19 and its relationship to stroke care throughout a 14- hospital stroke system. Results: The report allowed region-wide identification and evaluation of several metrics, including: volume of code strokes, the volume of patients who had a stroke within two weeks before or after testing positive for COVID-19, the initial NIHSS, if alteplase was administered, reason for no alteplase administration, delay in alteplase administration and if related to COVID-19 and the relationship of COVID-19 cases to the volume of code strokes. It was found that the volume of code strokes significantly decreased during the time of the pandemic and was inversely related to the volume of COVID-19 positive cases being reported in a county. The tool also found that COVID-19 positive stroke patients increased as the overall COVID-19 hospital volume increased. Conclusion: Assessing the relationships between a novel disease and other disease states may lead to changes in hospital workflows and practices resulting into improved patient outcomes.

Vasopressin Increases GABAergic Inhibition of Rat Hypothalamic Paraventricular Nucleus Neurons In Vitro

2000 ◽  
Vol 83 (2) ◽  
pp. 705-711 ◽  
Author(s):  
M.L.H.J. Hermes ◽  
J. M. Ruijter ◽  
A. Klop ◽  
R. M. Buijs ◽  
L. P. Renaud
Keyword(s):  
Paraventricular Nucleus ◽  
Receptor Agonist ◽  
Hypothalamic Paraventricular Nucleus ◽  
Membrane Properties ◽  
Magnocellular Neurons ◽  
Membrane Hyperpolarization ◽  
Perforated Patch ◽  
Intrinsic Membrane Properties ◽  
Brain Slice Preparation

This investigation used an in vitro hypothalamic brain slice preparation and whole cell and perforated-patch recording to examine the response of magnocellular neurons in hypothalamic paraventricular nucleus (PVN) to bath applications of vasopressin (VP; 100–500 nM). In 22/38 cells, responses were characterized by an increase in the frequency of bicuculline-sensitive inhibitory postsynaptic potentials or currents with no detectable influence on excitatory postsynaptic events. Perforated-patch recordings confirmed that VP did not have an effect on intrinsic membrane properties of magnocellular PVN neurons ( n = 17). Analysis of intrinsic membrane properties obtained with perforated-patch recording ( n = 23) demonstrated that all of nine VP-sensitive neurons showed a rebound depolarization after transient membrane hyperpolarization from rest. By contrast, 12/14 nonresponding neurons displayed a delayed return to resting membrane potentials. Recordings of reversed inhibitory postsynaptic currents with chloride-loaded electrodes showed that responses to VP persisted in media containing glutamate receptor antagonists but were abolished in the presence of tetrodotoxin. In addition, responses were mimicked by vasotocin [Phe2, Orn8], a selective V1a receptor agonist, and blocked by [β-Mercapto-β,β-cyclopentamethylenepropionyl1,O-Me-Tyr2, Arg8]-VP (Manning compound), a V1a/OT receptor antagonist. Neither [deamino-Cys1,Val4,d-Arg8]-VP, a selective V2 receptor agonist, nor oxytocin were effective. Collectively, the results imply that VP acts at V1a receptors to excite GABAergic neurons that are presynaptic to a population of magnocellular PVN neurons the identity of which features a unique rebound depolarization. Endogenous sources of VP may be VP-synthesizing neurons in suprachiasmatic nucleus, known to project toward the perinuclear regions of PVN, and/or the magnocellular neurons within PVN.

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