Circumventricular Organs

2013 ◽  
pp. 1-14 ◽  
Author(s):  
Alastair Ferguson
Keyword(s):  
Circumventricular Organs

scholarly journals Neurological and Neuropsychological Changes Associated with SARS-CoV-2 Infection: New Observations, New Mechanisms

2021 ◽  
pp. 107385842098410
Author(s):  
Muhammad Ali Haidar ◽  
Hussam Jourdi ◽  
Zeinab Haj Hassan ◽  
Ohanes Ashekyan ◽  
Manal Fardoun ◽  
...  
Keyword(s):  
Viral Entry ◽  
Health Workers ◽  
The Elderly ◽  
Circumventricular Organs ◽  
Depression And Anxiety ◽  
Virus Surface ◽  
Angiotensin Converting Enzyme 2 ◽  
Neuropsychological Changes ◽  
High Risk Populations ◽  
The Central Nervous System

SARS-CoV-2 infects cells through angiotensin-converting enzyme 2 (ACE2), a ubiquitous receptor that interacts with the virus’ surface S glycoprotein. Recent reports show that the virus affects the central nervous system (CNS) with symptoms and complications that include dizziness, altered consciousness, encephalitis, and even stroke. These can immerge as indirect immune effects due to increased cytokine production or via direct viral entry into brain tissue. The latter is possible through neuronal access via the olfactory bulb, hematogenous access through immune cells or directly across the blood-brain barrier (BBB), and through the brain’s circumventricular organs characterized by their extensive and highly permeable capillaries. Last, the COVID-19 pandemic increases stress, depression, and anxiety within infected individuals, those in isolation, and high-risk populations like children, the elderly, and health workers. This review surveys the recent updates of CNS manifestations post SARS-CoV-2 infection along with possible mechanisms that lead to them.

Sensory circumventricular organs and brain homeostatic pathways

1993 ◽  
Vol 7 (8) ◽  
pp. 678-686 ◽  
Author(s):  
Alan Kim Johnson ◽  
Paul M. Gross
Keyword(s):  
Circumventricular Organs

Fluorescein-Enhanced Characterization of Additional Anatomical Landmarks in Cerebral Ventricular Endoscopy

Neurosurgery ◽  
2013 ◽  
Vol 72 (5) ◽  
pp. 855-860 ◽  
Author(s):  
Pierluigi Longatti ◽  
Luca Basaldella ◽  
Francesco Sammartino ◽  
Alessandro Boaro ◽  
Alessandro Fiorindi
Keyword(s):  
Choroid Plexus ◽  
White Light ◽  
Area Postrema ◽  
Functional Anatomy ◽  
Circumventricular Organs ◽  
Third Ventriculostomy ◽  
Cancer Tissue ◽  
Anatomical Landmarks ◽  
Fluorescein Sodium ◽  
Anatomic Landmarks

Abstract BACKGROUND: Fluorescein enhancement to detect retinal disorder or differentiate cancer tissue in situ is a well-defined diagnostic procedure. It is a visible marker of where the blood-brain barrier is absent or disrupted. Little is reported in the contemporary literature on endoscopic fluorescein-enhanced visualization of the circumventricular organs, and the relevance of these structures as additional markers for safe ventricular endoscopic navigation remains an unexplored field. OBJECTIVE: To describe fluorescein sodium–enhanced visualization of circumventricular organs as additional anatomic landmarks during endoscopic ventricular surgery procedures. METHODS: We prospectively administered intravenously 500 mg fluorescein sodium in 12 consecutive endoscopic surgery patients. A flexible endoscope equipped with dual observation modes for both white light and fluorescence was used. During navigation from the lateral to the fourth ventricle, the endoscopic anatomic landmarks were first inspected under white light and then under the fluorescent mode. RESULTS: After a mean of 20 seconds in the fluorescent mode, the fluorescein enhanced visualization of the choroid plexus of the lateral ventricle, median eminence–tuber cinereum complex, organum vasculosum of the lamina terminalis, choroid plexus of the third and fourth ventricles, and area postrema. CONCLUSION: Fluorescein-enhanced visualization is a useful tool for helping neuroendoscopists recognize endoscopic anatomic landmarks. It could be adopted to guide orientation when the surgeon deems an endoscopic procedure unsafe or contraindicated because of unclear or subverted anatomic landmarks. Visualization of the circumventricular organs could add new insight into the functional anatomy of these structures, with possible implications for the site and safety of third ventriculostomy.

Elevation of sodium levels in the cerebral ventricles of anaesthetized dogs triggers the release of an inhibitor of ouabain-sensitive sodium, potassium-ATPase into the circulation

1986 ◽  
Vol 70 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Bhagavan S. Jandhyala ◽  
Ahmad F. Ansari
Keyword(s):  
Blood Vessels ◽  
Circumventricular Organs ◽  
Plasma Samples ◽  
Cerebral Ventricles ◽  
Sodium Potassium ◽  
Natriuretic Hormone ◽  
Circulating Blood Volume ◽  
Na Pump ◽  
Artificial Cerebrospinal Fluid ◽  
Uptake Method

1. The present studies are designed to determine whether a ouabain-sensitive inhibitor of Na+, K+−stimulated ATPase is released into the circulation when the Na+ levels are elevated in the cerebral ventricles in pentobarbital anaesthetized dogs. Na+−pump activity was estimated in the plantar and dorsal branches of the lateral saphenous veins by using the 86Rb-uptake method. 2. Infusion of the cerebral ventricles with the artificial cerebrospinal fluid (CSF) containing normal Na+ (0.15 mol/l) for over 120 min resulted in significant increases in only ouabain-sensitive 86Rb-uptake. In contrast, when the ventricles were perfused with the CSF containing high Na+ (0.3 mol/l) for similar periods, there were significant reductions in the ouabain-sensitive as well as in ouabain-insensitive 86Rb-uptake by the blood vessels. 3. Similar blood vessels from a separate group of dogs were incubated for 120 min in the plasma samples collected from the above groups in which normal or hypertonic Na+ solutions were infused. The data showed that ouabain-sensitive 86Rb-uptake (but not the insensitive component) was significantly inhibited only in those vessels which were incubated in the plasma samples that were obtained at 120 min after perfusion of the cerebral ventricles with CSF containing high Na+ (0.3 mol/l). 4. These studies have provided direct evidence which would suggest that the elevation of Na+ levels in the cerebral ventricles would precipitate the release of an inhibitor of the ouabain-sensitive Na+−pump into the circulation, perhaps due to an activation of Na+−sensitive and/or osmo-sensitive sites in the circumventricular organs. It is hypothesized that this humoral substance may be the same ‘natriuretic hormone’ which is released after acute expansion of circulating blood volume.

scholarly journals Tanycyte-like cells form a blood-cerebrospinal fluid barrier in the circumventricular organs of the mouse brain

2013 ◽  
Vol 521 (15) ◽  
pp. 3389-3405 ◽  
Author(s):  
Fanny Langlet ◽  
Amandine Mullier ◽  
Sebastien G. Bouret ◽  
Vincent Prevot ◽  
Benedicte Dehouck
Keyword(s):  
Cerebrospinal Fluid ◽  
Mouse Brain ◽  
Circumventricular Organs

Vasopressin mRNA in the cerebellum and circumventricular organs: a quantitative in situ hybridization study

1993 ◽  
Vol 159 (1-2) ◽  
pp. 171-174 ◽  
Author(s):  
Patrick Lepetit ◽  
Michelle Fevre-Montange ◽  
Nadine Gay ◽  
Marie-Françoise Belin ◽  
Pierre Bobillier
Keyword(s):  
In Situ Hybridization ◽  
Circumventricular Organs ◽  
Hybridization Study

scholarly journals Effect of sex chromosome complement on sodium appetite and Fos-immunoreactivity induced by sodium depletion

2014 ◽  
Vol 306 (3) ◽  
pp. R175-R184 ◽  
Author(s):  
Florencia M. Dadam ◽  
Ximena E. Caeiro ◽  
Carla D. Cisternas ◽  
Ana F. Macchione ◽  
María J. Cambiasso ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Area Postrema ◽  
Brain Activity ◽  
Chromosome Complement ◽  
Circumventricular Organs ◽  
Sexually Dimorphic ◽  
Sodium Depletion ◽  
Sodium Diet ◽  
Sodium Appetite ◽  
Low Sodium Diet

Previous studies indicate a sex chromosome complement (SCC) effect on the angiotensin II-sexually dimorphic hypertensive and bradycardic baroreflex responses. We sought to evaluate whether SCC may differentially modulate sexually dimorphic-induced sodium appetite and specific brain activity due to physiological stimulation of the rennin angiotensin system. For this purpose, we used the “four core genotype” mouse model, in which the effect of gonadal sex and SCC is dissociated, allowing comparisons of sexually dimorphic traits between XX and XY females as well as in XX and XY males. Gonadectomized mice were sodium depleted by furosemide (50 mg/kg) and low-sodium diet treatment; control groups were administered with vehicle and maintained on normal sodium diet. Twenty-one hours later, the mice were divided into two groups: one group was submitted to the water-2% NaCl choice intake test, while the other group was perfused and their brains subjected to the Fos-immunoreactivity (FOS-ir) procedure. Sodium depletion, regardless of SCC (XX or XY), induced a significantly lower sodium and water intake in females than in males, confirming the existence in mice of sexual dimorphism in sodium appetite and the organizational involvement of gonadal steroids. Moreover, our results demonstrate a SCC effect on induced brain FOS-ir, showing increased brain activity in XX-SCC mice at the paraventricular nucleus, nucleus of the solitary tract, and lateral parabrachial nucleus, as well as an XX-SCC augmented effect on sodium depletion-induced brain activity at two circumventricular organs, the subfornical organ and area postrema, nuclei closely involved in fluid and blood pressure homeostasis.

Sodium depletion induces Fos immunoreactivity in circumventricular organs of the lamina terminalis

1995 ◽  
Vol 679 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Laura Vivas ◽  
Cinthia Veronica Pastuskovas ◽  
Leonardo Tonelli
Keyword(s):  
Circumventricular Organs ◽  
Lamina Terminalis ◽  
Sodium Depletion
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