Distribution of orexin neurons in the adult rat brain

This review discusses the central nervous system actions of the circulating hormone, angiotensin II. Access of this peptide likely is limited to those central structures which lack the blood-brain barrier. Three of the circumventricular organs, the area postrema, the subfornical organ, and the organum vasculosum, have all been suggested to be sites of action for angiotensin within the brain. The area postrema is a site of pressor action of angiotensin in many species but not in the rat. The subfornical organ is a site where angiotensin provokes drinking, a pressor effect, and the secretion of vasopressin. The organum vasculosum and adjacent tissue has also been suggested to be a site for these three central effects of the peptide. Blood-borne angiotensin probably does not act at the same locus as does angiotensin applied to the brain via its ventricular system.

Area postrema

Circumventricular organs

Osmoreceptor

10.1159/000123167

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Citations (324)

Brain Angiotensin II Receptor Subtypes

Springer eBooks (1994)

Juan M. Saavedra

Circumventricular organs

Area postrema

Lamina terminalis

Median eminence

10.1007/978-1-4615-2464-9_8

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Citations (15)

Circumventricular Organs

Elsevier eBooks (2004)

Michael J. McKinley Iain J. Clarke Brian J. Oldfield

Circumventricular organs

Area postrema

Subcommissural organ

Median eminence

Lamina terminalis

Ependymal Cell

10.1016/b978-012547626-3/50020-x

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Citations (21)

Circumventricular Organs in Neuroendocrine Control

Elsevier eBooks (2009)

Alan Kim Johnson

Circumventricular organs

Lamina terminalis

Area postrema

Median eminence

10.1016/b978-008045046-9.01167-0

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Citations (1)

Heroin sensitization induces circumventricular organ activation in the rat brain.

PubMed (2005)

Loredana D’Este Arianna Casini Francesco E. Pontieri T Renda

Using c-Fos protein immunohistochemistry we previously demonstrated various sites of activation in the rat forebrain according to the animal's drug history. This study originates from a more detailed evaluation ex-post of the same specimens. A discrete number of c-Fos protein immunoreactive nuclei could be observed in some circumventricular organs, including the vascular organ of terminal lamina (OVLT) and subfornical organ (SFO) and in the nucleus of solitary tract near the area postrema, but only in specimens from sensitized rats. We therefore suggest that repeated drug injections activate the normally low drug metabolizing enzyme activity in the circumventricular organs thus implicating these organs in the complex mechanisms underlying behavioral sensitization.

Area postrema

Circumventricular organs

Solitary tract

Forebrain

Solitary nucleus

Source

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Citations (1)

Neuronal activity and CRF receptor gene transcription in the brains of rats with colitis

AJP Gastrointestinal and Liver Physiology (2004)

Christophe Porcher Valérie Sinniger Aurélie Juhem Patrick Mouchet Bruno Bonaz

We aimed to characterize neuronal and corticotropin-releasing factor (CRF) pathways at the acute phase of a model of colitis in rats. Male rats received an intracolonic injection of either vehicle (controls) or trinitrobenzenesulfonic acid (TNBS) and were killed 1, 2, 3, 4, 6, 12, or 24 h later. Coronal frozen sections of the brain were cut and mRNAs encoding the rat c-fos, CRF1 receptor, and CRF2alpha,beta receptors were assayed by in situ hybridization histochemistry. Localization of these transcripts within CRF-immunoreactive (CRF-ir) neurons of the paraventricular nucleus (PVN) of the hypothalamus was also determined. Intracolonic TNBS induced c-fos mRNA expression in brain nuclei involved in the autonomic, behavioral, and neuroendocrine response to a stimulus (PVN, amygdala, locus coeruleus, parabrachial nucleus, nucleus of the solitary tract) and in circumventricular organs (lamina terminalis, subfornical organ, area postrema). CRF pathways, particularly in the PVN, were activated in this model as represented by a robust signal of c-fos and CRF1 receptor transcripts in the PVN and numerous CRF-ir neurons expressed c-fos or CRF1 receptor transcripts in the PVN of TNBS-treated animals. No expression of CRF2 receptor transcripts was observed in the PVN, either in basal conditions or after TNBS. These neuroanatomical data argue for an involvement of CRF pathways, through CRF1 receptor, within the PVN in TNBS-induced colitis.

Area postrema

Circumventricular organs

Lateral parabrachial nucleus

Solitary tract

Immediate early gene

c-Fos

Periventricular nucleus

10.1152/ajpgi.00135.2004

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Citations (27)

Aquaporin-1 in blood vessels of rat circumventricular organs

Cell and Tissue Research (2010)