Organum cavum pre-lamina terminalis, an undescribed brain organ in rats: morphology and physiology

1991 ◽  
Vol 260 (2) ◽  
pp. R396-R406
Author(s):  
S. Nicolaidis ◽  
M. el Ghissassi
Keyword(s):  
Angiotensin Ii ◽  
Corpus Callosum ◽  
High Sensitivity ◽  
Ventricular System ◽  
Lamina Terminalis ◽  
Cavum Septi Pellucidi ◽  
Brain Functions ◽  
Anterior Aspect ◽  
Electrolyte Homeostasis ◽  
Subarachnoid Spaces

Morphological as well as physiological findings reported here point to the existence of a previously undescribed brain organ we refer to as the organum cavum pre-lamina terminalis (OCPLT). The organ is a hollow, sagittal, forebrain structure consisting of a vertical interhemispheric horn that overlies the anterior aspect of the lamina terminalis and a horizontal horn that lies in the septum below the corpus callosum. This horizontal horn was previously referred to as the cavum septi pellucidi, a vestigial anatomic curiosity. The narrow cavities of the horizontal and vertical horns join under the genu of the corpus callosum and communicate freely. The two horns do not communicate with the cerebral ventricular system or the subarachnoid spaces. Microinjections of greater than or equal to 0.2 ng angiotensin II into all regions of the cavity resulted in significant drinking, whereas injections into areas surrounding the cavities were ineffective. These data show that the organ is a discrete brain entity and displays high sensitivity to angiotensin II. These findings suggest that the OCPLT is another brain organ with significant effects on fluid and electrolyte homeostasis and perhaps other brain functions.

Angiotensin II-induced thirst, but not sodium appetite, via AT1 receptors in organum cavum prelamina terminalis

1995 ◽  
Vol 268 (6) ◽  
pp. R1401-R1405 ◽  
Author(s):  
M. el Ghissassi ◽  
S. N. Thornton ◽  
S. Nicolaidis
Keyword(s):  
Angiotensin Ii ◽  
Salt Intake ◽  
High Sensitivity ◽  
Ang Ii ◽  
Nacl Solution ◽  
At1 Receptors ◽  
Sodium Appetite ◽  
Specific Antagonist

The angiotensin receptor specificity, with respect to fluid intake, of the organum cavum prelamina terminalis (OCPLT), a recently discovered discrete forebrain structure with high sensitivity to angiotensin II (ANG II), was investigated. ANG II (10 ng) microinjected into the OCPLT significantly increased water consumption but did not induce intake of a hypertonic (3%) NaCl solution. Losartan, an ANG II type 1 (AT1) receptor-specific antagonist, produced dose-related (1-100 ng) inhibition of ANG II-induced drinking. The ANG II type 2 receptor-specific antagonist CGP-42112A was ineffective. Intake of the 3% NaCl solution in response to microinjection of either of the antagonists into the OCPLT was never observed. These findings suggest that water intake produced by microinjection of ANG II into the OCPLT is mediated by AT1 receptors uniquely and that, in contrast to other regions of the brain, these receptors do not induce salt intake when stimulated by ANG II.

scholarly journals Neuroimaging in normal pressure hydrocephalus

2015 ◽  
Vol 9 (4) ◽  
pp. 350-355 ◽  
Author(s):  
Benito Pereira Damasceno
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Cerebral Atrophy ◽  
High Sensitivity ◽  
Normal Pressure ◽  
Evans Index ◽  
Flow Void ◽  
High Positive Predictive Value ◽  
Subarachnoid Spaces ◽  
Magnetic Resonance Imaging Mri ◽  
Improved Accuracy

ABSTRACT Normal pressure hydrocephalus (NPH) is a syndrome characterized by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation (triad) may be atypical or incomplete, or mimicked by other diseases, hence the need for supplementary tests, particularly to predict postsurgical outcome, such as CSF tap-tests and computed tomography (CT) or magnetic resonance imaging (MRI). The CSF tap-test, especially the 3 to 5 days continuous external lumbar drainage of at least 150 ml/day, is the only procedure that simulates the effect of definitive shunt surgery, with high sensitivity (50-100%) and high positive predictive value (80-100%). According to international guidelines, the following are CT or MRI signs decisive for NPH diagnosis and selection of shunt-responsive patients: ventricular enlargement disproportionate to cerebral atrophy (Evans index >0.3), and associated ballooning of frontal horns; periventricular hyperintensities; corpus callosum thinning and elevation, with callosal angle between 40º and 90º; widening of temporal horns not fully explained by hippocampal atrophy; and aqueductal or fourth ventricular flow void; enlarged Sylvian fissures and basal cistern, and narrowing of sulci and subarachnoid spaces over the high convexity and midline surface of the brain. On the other hand, other imaging methods such as radionuclide cisternography, SPECT, PET, and also DTI or resting-state functional MRI, although suitable for NPH diagnosis, do not yet provide improved accuracy for identifying shunt-responsive cases.

scholarly journals EP08.15: Cavum septi pellucidi (CSP) ratio: is it also a marker for dysgenesis of the corpus callosum?

2019 ◽  
Vol 54 (S1) ◽  
pp. 281-281
Author(s):  
J. Miguelez ◽  
M.H. Carvalho ◽  
E.Q. Barreto ◽  
W. Hisaba
Keyword(s):  
Corpus Callosum ◽  
Cavum Septi Pellucidi

scholarly journals Evaluation of Systemic Renin and Angiotensin II Levels in Normal Tension Glaucoma

2020 ◽  
Vol 9 (12) ◽  
pp. 3838
Author(s):  
Soo Ji Jeon ◽  
Hyung Bin Hwang ◽  
Na Young Lee
Keyword(s):  
Angiotensin Ii ◽  
Complete Blood Count ◽  
Low Density Lipoprotein ◽  
Multivariate Logistic Regression Analysis ◽  
Density Lipoprotein ◽  
High Sensitivity ◽  
Normal Tension Glaucoma ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reactive Protein ◽  
Hs Crp

The purpose of this study was to investigate the function of the renin–angiotensin–aldosterone system (RAAS) in normal tension glaucoma (NTG) patients by measuring the level of renin and angiotensin II (AngII) in the plasma. Twenty-four patients with NTG and 38 control subjects were included in this study. Renin and AngII were measured in the blood samples of all subjects by enzyme-linked immunosorbent assay (ELISA). No significant differences were found in the complete blood count, fasting glucose, low-density lipoprotein (LDL), and high-sensitivity C-reactive protein (hs-CRP) levels between the control and NTG groups. The systemic concentration and variability of the renin concentration in the blood was significantly higher in the NTG group (p = 0.005 and 0.005, respectively). According to multivariate logistic regression analysis, the variability of the renin concentration was associated with NTG (p = 0.006). In conclusion, the systemic concentration and variability of renin levels were elevated in NTG patients. An altered renin concentration could represent a difference in RAAS function in NTG patients.

Effect of intravenous angiotensin II on Fos distribution and drinking behavior in rabbits

1997 ◽  
Vol 272 (5) ◽  
pp. R1515-R1524 ◽  
Author(s):  
E. Badoer ◽  
D. McKinlay
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Intravenous Infusion ◽  
Drinking Behavior ◽  
Ventrolateral Medulla ◽  
Lamina Terminalis ◽  
Ang Ii ◽  
Solitary Tract ◽  
Cell Nuclei ◽  
Drinking Response

We investigated the effect of intravenous infusion of angiotensin II (ANG II, 40 ng.kg-1.min-1) on the distribution of Fos in the subfornical organ (SFO), organum vasculosum of the lamina terminalis (OVLT), and the medulla of the conscious rabbit. ANG II elicited significant increases in the number of Fos-positive cell nuclei in the SFO and OVLT (15- and 10-fold, respectively). Raising blood pressure with phenylephrine did not elicit Fos in these nuclei. These nuclei are believed to be responsible for the dipsogenic actions of ANG II; however, ANG II was not dipsogenic. When blood pressure was held at preinfusion levels by the coadministration of sodium nitroprus-side and ANG II, the rabbits did not drink but Fos production in the lamina terminalis was elevated. In the medulla, ANG II did not significantly increase Fos production in the nucleus of the solitary tract (NTS) or ventrolateral medulla (VLM). However, with the coadministration of sodium nitroprusside, there were marked increases in the NTS and VLM. The results suggest that neurons in the SFO and OVLT are either not involved in the dipsogenic pathways or there is disruption further downstream in the central pathways that would normally mediate a drinking response to ANG II.

Impermeability of the Blood—Cerebrospinal Fluid Barrier for Angiotensin II in Rats

1976 ◽  
Vol 51 (s3) ◽  
pp. 399s-402s ◽  
Author(s):  
P. Schelling ◽  
J. S. Hutchinson ◽  
U. Ganten ◽  
G. Sponer ◽  
D. Ganten
Keyword(s):  
Cerebrospinal Fluid ◽  
Angiotensin Ii ◽  
Intravenous Infusion ◽  
Ventricular System ◽  
Cisterna Magna ◽  
Biochemical Methods ◽  
Intravenous Infusions ◽  
Artificial Cerebrospinal Fluid ◽  
Brain Ventricular System ◽  
The Brain

1. Anaesthetized, nephrectomized rats were infused intravenously with unlabelled angiotensin II (AII) or with [3H]angiotensin II (3H-labelled AII). The brain ventricular system was perfused with artificial cerebrospinal fluid. The perfusate was collected from the cisterna magna and analysed for AII by radioimmunological and biochemical methods. 2. No increase of immunoreactive AII in cerebrospinal fluid could be shown during intravenous infusion of AII. 3. During intravenous infusions of 3H-labelled AII at pressor doses small amounts of radioactivity were found in cerebrospinal fluid perfusate. 4. The radioactivity of cerebrospinal fluid outflow could not be related to AII.

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