Objectives: Circumventricular organs (CVOs) are fine, periventricular, neurotransmitter-rich structures that are devoid of a blood-brain barrier and are known for their secretory role controlling fluid and electrolyte balance, thirst and even reproduction. Common pathologies of the brain such as trauma or bleeding affect CVOs, and hence their function. However, at what stage of these disease processes are CVOs affected and the time sequence of their recovery is still not clear. The aim of this study was to detect the morphological changes in CVOs using electron microscopy after experimental subarachnoid hemorrhage (SAH).
Methods: Experimental SAH was induced by transclival puncture of the basilar artery. Both scanning and transmission electron microscopic examination of the representive sections from each CVO was undertaken.
Results: Electron microscopy has shown that after SAH, the cells that form the CVOs exhibit signs of cellular necrosis with margination of the nucleus as well as cytoplasmic, mitochondrial and axonal edema. The subfornicial organ and organum vasculosum lamina terminalis appear to be more vulnerable to the effects of SAH than the median eminence or area postrema.
Discussion: Considering the fact that the experimental SAH model we have used is very similar to the momentary rupture of an aneurysm with secondary reflex spasm to seal the hole, it will not be unrealistic to consider that similar effects may also take place in the clinical setting.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1179/016164105X48752 | DOI Listing |
Biomed Pharmacother
December 2024
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58102, United States. Electronic address:
Neurogenic hypertension (NH) is characterized by heightened sympathetic activity mediated by angiotensin II in specific brain areas including the paraventricular nucleus and circumventricular organs. While strategies targeting sympathetic activity have shown effectiveness in managing NH, their invasive nature hinders their widespread clinical adoption. Conversely, nose-to-brain drug delivery is emerging as a promising approach to access the brain with reduced invasiveness.
View Article and Find Full Text PDFMetab Brain Dis
December 2024
Institute of Neurology (Edinger Institute), University Hospital, Goethe University Frankfurt, Frankfurt am Main, Germany.
The blood-brain barrier (BBB) is formed by microvascular endothelial cells which are ensembled with pericytes, astrocytes, microglia and neurons in the neurovascular unit (NVU) that is crucial for neuronal function. Given that the NVU and the BBB are highly dynamic and regulated structures, their integrity is continuously challenged by intrinsic and extrinsic factors. Herein, factors from peripheral organs such as gonadal and adrenal hormones may influence vascular function also in CNS endothelial cells in a sex- and age-dependent manner.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
University of Manitoba, Department of Biological Sciences, Winnipeg, MB, Canada, R3X0B5. Electronic address:
The subfornical organ (SFO) is a sensory circumventricular organ of the central nervous system and plays a key role in regulation of a number of homeostatic processes because of its ability to detect and respond to circulating signals and communication to homeostatic control centres. A previous study reported a change in expression of 687 transcripts in rat SFO following a 48h fast; of particular interest was the observed downregulation of the transcript encoding the Nav1.3 voltage-gated Na channel.
View Article and Find Full Text PDFScience
November 2024
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.
Water deprivation is a life-threatening condition that engages a protective physiological response to couple osmolyte retention with potentiation of thirst. This response, typical for most mammals, safeguards against short-term water deprivation but fails in the long term. Thirteen-lined ground squirrels () use the short-term response during summer, whereas during winter, they lack thirst and survive without water for months.
View Article and Find Full Text PDFSci Adv
November 2024
Department of Anesthesiology, Zhongshan Hospital Fudan University, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and the Institutes of Brain Science, Fudan University, Shanghai 200032, China.
Peripheral inflammation is closely related to the pathogenesis of sickness behaviors and psychiatric disorders such as anxiety and depression. The circumventricular organs (CVOs) are important brain sites to perceive peripheral inflammatory signals, but few studies have reported their role in inflammation-induced anxiety or depression. Using a mouse model of lipopolysaccharide (LPS)-induced inflammation, we identified a previously unreported role of the subfornical organ (SFO), one of the CVOs, in combating inflammation-induced anxiety.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!