Monoamine innervation of the organum vasculosum laminae terminalis (OVLT): A high resolution radioautographic study in the rat

1988 ◽  
Vol 272 (4) ◽  
pp. 545-561 ◽  
Author(s):  
Olivier Bosler ◽  
Laurent Descarries
Keyword(s):  
High Resolution ◽  
Organum Vasculosum Laminae Terminalis ◽  
Organum Vasculosum

The organum vasculosum laminae terminalis in immune-to-brain febrigenic signaling: a reappraisal of lesion experiments

2003 ◽  
Vol 285 (2) ◽  
pp. R420-R428 ◽  
Author(s):  
Andrej A. Romanovsky ◽  
Naotoshi Sugimoto ◽  
Christopher T. Simons ◽  
William S. Hunter
Keyword(s):  
Side Effects ◽  
Isotonic Saline ◽  
Alternative Interpretation ◽  
Sprague Dawley ◽  
Febrile Response ◽  
Drinking Response ◽  
Organum Vasculosum Laminae Terminalis ◽  
Sprague Dawley Rats ◽  
Organum Vasculosum ◽  
The Brain

The organum vasculosum laminae terminalis (OVLT) has been proposed to serve as the interface for blood-to-brain febrigenic signaling, because ablation of this structure affects the febrile response. However, lesioning the OVLT causes many “side effects” not fully accounted for in the fever literature. By placing OVLT-lesioned rats on intensive rehydration therapy, we attempted to prevent these side effects and to evaluate the febrile response in their absence. After the OVLT of Sprague-Dawley rats was lesioned electrolytically, the rats were given access to 5% sucrose for 1 wk to stimulate drinking. Sucrose consumption and body mass were monitored. The animals were examined twice a day for signs of dehydration and treated with isotonic saline (50 ml/kg sc) when indicated. This protocol eliminated mortality but not several acute and chronic side effects stemming from the lesion. The acute effects included adipsia and gross (14% of body weight) emaciation; chronic effects included hypernatremia, hyperosmolality, a suppressed drinking response to hypertonic saline, and previously unrecognized marked (by ∼2°C) and long-lasting (>3 wk) hyperthermia. Because the hyperthermia was not accompanied by tail skin vasoconstriction, it likely reflected increased thermogenesis. After the rats recovered from the acute (but not chronic) side effects, their febrile response to IL-1β (500 ng/kg iv) was tested. The sham-operated rats developed typical monophasic fevers (∼0.5°C), the lesioned rats did not. However, the absence of the febrile response in the OVLT-lesioned rats likely resulted from the untreatable side effects. For example, hyperthermia at the time of pyrogen injection was high enough (39–40°C) to solely prevent fever from developing. Hence, the changed febrile responsiveness of OVLT-lesioned animals is given an alternative interpretation, unrelated to febrigenic signaling to the brain.

scholarly journals Topological and histological description of preoptic area and hypothalamus in cardinal tetra Paracheirodon axelrodi (Characiformes: Characidae)

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Laura Rincón ◽  
Martha J. Obando ◽  
Mario O. Tovar ◽  
Matías Pandolfi ◽  
Hernan Hurtado
Keyword(s):  
High Resolution ◽  
Preoptic Area ◽  
Staining Pattern ◽  
Lamina Terminalis ◽  
Preoptic Nucleus ◽  
Paraffin Sections ◽  
Neuron Morphology ◽  
Organum Vasculosum ◽  
Optic Microscopy ◽  
Nissl Technique

ABSTRACT Topological and histological descriptions of the preoptic area and hypothalamus of the cardinal tetra Paracheirodon axelrodi were performed. Standard histological paraffin sections were used and stained with Nissl technique, and plastic sections for high-resolution optic microscopy (HROM). The preoptic area showed some differences related to the location of the magnocellular preoptic nucleus (PM) and the size of the neurons in this region, as they were the biggest in all the preoptic area. Additionally, within the preoptic area, the different structures that comprise the organum vasculosum of the lamina terminalis (OVLT) were identified and characterized. The hypothalamus could be subdivided in three regions - the ventral, the dorsal and the caudal hypothalamic regions - neuron morphology, size and staining pattern were similar in all of them.

Increases in brain and cardiac AT1 receptor and ACE densities after myocardial infarct in rats

2004 ◽  
Vol 286 (5) ◽  
pp. H1665-H1671 ◽  
Author(s):  
Junhui Tan ◽  
Hao Wang ◽  
Frans H. H. Leenen
Keyword(s):  
Paraventricular Nucleus ◽  
Receptor Binding ◽  
Myocardial Infarct ◽  
Subfornical Organ ◽  
Preoptic Nucleus ◽  
Fab Fragments ◽  
Intracerebroventricular Infusion ◽  
Organum Vasculosum Laminae Terminalis ◽  
Organum Vasculosum ◽  
The Brain

In the brain, ouabain-like compounds (OLC) and the reninangiotensin system (RAS) contribute to sympathetic hyperactivity in rats after myocardial infarction (MI). This study aimed to evaluate changes in components of the central vs. the peripheral RAS. Angiotensin-converting enzyme (ACE) and angiotensin type 1 (AT1) receptor binding densities were determined by measuring 125I-labeled 351A and 125I-labeled ANG II binding 4 and 8 wk after MI. In the brain, ACE and AT1 receptor binding increased 8–15% in the subfornical organ, 14–22% in the organum vasculosum laminae terminalis, 20–34% in the paraventricular nucleus, and 13–15% in the median preoptic nucleus. In the heart, the greatest increase in ACE and AT1 receptor binding occurred at the infarct scar (∼10-fold) and the least in the right ventricle (2-fold). In kidneys, ACE and AT1 receptor binding decreased 10–15%. After intracerebroventricular infusion of Fab fragments to block brain OLC from 0.5 to 4 wk after MI, increases in ACE and AT1 receptors in the subfornical organ, organum vasculosum laminae terminalis, paraventricular nucleus, and medial preoptic nucleus were markedly inhibited, and ACE and AT1 receptor densities in the heart increased less (6-fold in the infarct scar). In kidneys, decreases in ACE and AT1 receptor binding were absent after treatment with Fab fragments. These results demonstrate that ACE and AT1 receptor binding densities increase not only in the heart but also in relevant areas of the brain of rats after MI. Brain OLC appears to play a major role in activation of brain RAS in rats after MI and, to a modest degree, in activation of the cardiac RAS.

Role of the organum vasculosum laminae terminalis in the control of gonadotrophin secretion in rats

1982 ◽  
Vol 93 (3) ◽  
pp. 355-NP ◽  
Author(s):  
F. Piva ◽  
P. Limonta ◽  
L. Martini
Keyword(s):  
Ovariectomized Rats ◽  
Adult Rats ◽  
Organum Vasculosum Laminae Terminalis ◽  
Serum Lh ◽  
Parallel Increase ◽  
Gonadotrophin Secretion ◽  
Radiofrequency Lesions ◽  
Organum Vasculosum

The organum vasculosum laminae terminalis (OVLT) was destroyed by radiofrequency lesions in regularly cycling and in long-term ovariectomized adult rats. After OVLT lesion practically all cyclic females (16 out of 22) became dioestrous, as indicated by vaginal smears. At the time of killing these animals (8 days after the lesion) serum LH levels were undetectable, while serum FSH was as low as in cyclic animals in dioestrus. In the few OVLT-lesioned animals which exhibited some sort of oestrous cyclicity, serum LH showed a small subphysiological increase at pro-oestrus: this was not accompanied by a parallel increase in serum FSH and in these animals a delayed peak of FSH occurred on the day of oestrus. Ovariectomized rats bearing OVLT lesions had serum titres of LH and FSH as high as those of ovariectomized control rats. It is suggested that the OVLT may play a role in the control of the cyclic release of gonadotrophins but is not involved in the tonic regulation of gonadotrophin secretion.

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