Sur la vascularisation du tuber postérieur chez l'homme et sur les relations vasculaires tubérohypophysaires

Duvernoy, Henri M.; Koritke, J. G.; Monnier, G.

doi:10.1007/bf02310044

Cited by 28 publications

(11 citation statements)

References 19 publications

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“…Previous immunohistochemical studies from our laboratory [10,63] showed a highly abundant network of KP-IR axons around the portal vasculature of the human postinfundibular eminence which contains a superficial and a deep portal capillary plexus [100]. These observations raise the possibility that, unlike in rodents, KP is secreted into the hypophysial portal circulation of the human as a hypophysiotropic factor.…”

Section: Connections Of Kp Neuronsmentioning

confidence: 68%

Neuroanatomy of the Human Hypothalamic Kisspeptin System

Hrabovszky

2013

Neuroendocrinology

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Hypothalamic kisspeptin (KP) neurons are key players in the neuronal network that regulates the onset of puberty and the pulsatile secretion of gonadotropin-releasing hormone (GnRH). In various mammalian species, the majority of KP-synthesizing neurons are concentrated in two distinct cell populations in the preoptic region and the arcuate nucleus (ARC). While studies of female rodents have provided evidence that preoptic KP neurons play a critical sex-specific role in positive estrogen feedback, KP neurons of the ARC have been implicated in negative sex steroid feedback and they have also been hypothesized to contribute to the pulse generator network which regulates episodic GnRH secretion in both females and males. Except for relatively few morphological studies available in monkeys and humans, our neuroanatomical knowledge of the hypothalamic KP systems is predominantly based on observations of laboratory species which are phylogenetically distant from the human. This review article discusses the currently available literature on the topographic distribution, network connectivity, neurochemistry, sexual dimorphism, and aging-dependent morphological plasticity of the human hypothalamic KP neuronal system.

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Section: Connections Of Kp Neuronsmentioning

confidence: 68%

Neuroanatomy of the Human Hypothalamic Kisspeptin System

Hrabovszky

2013

Neuroendocrinology

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“…These GnRH projections were present in highest abundance in the postinfundibular eminence (fig. 1a-i) which contains a superficial and a deep plexus of hypophysial portal capillaries [45]. These capillary plexuses were surrounded by GnRH-IR axons and, at the same time, also by very dense KP-IR (fig.…”

Section: Resultsmentioning

confidence: 99%

“…It is possible that neuropeptides released from the varicosities of these axon plexuses reach the adenohypophysis via the short portal veins to influence gonadotroph functions. In addition, the secreted neuropeptides might directly enter the systemic circulation from the portal capillary plexuses of the postinfundibular eminence [45] and through the tuberal veins of the InfS. It is important to recognize that many neuropeptides present in the external zone of the sheep median eminence are not necessarily secreted in significant amounts into the hypophysial portal blood [54] and this can also be the case in primates.…”

Section: Discussionmentioning

confidence: 99%

“…The analysis was extended to SP-IR axons, many of which are identical with KP-IR and NKB-IR axons in the human [10]. The anatomical relationship of KP-IR [7], NKB-IR [7] and SP-IR [43] axons with GnRH-IR [44] axons was first studied around the postinfundibular eminence which contains the majority of the portal capillaries in the human [45]. GnRH axons in the human and the monkey enter the infundibular stalk (InfS), and many fibers descend all the way down to the neurohypophysis [44].…”

Section: Introductionmentioning

confidence: 99%

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Hypophysiotropic Gonadotropin-Releasing Hormone Projections Are Exposed to Dense Plexuses of Kisspeptin, Neurokinin B and Substance P Immunoreactive Fibers in the Human: A Study on Tissues from Postmenopausal Women

et al. 2014

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Neuronal populations that synthesize kisspeptin (KP), neurokinin B (NKB) and substance P (SP) in the hypothalamic infundibular nucleus of humans are partly overlapping. These cells are important upstream regulators of gonadotropin-releasing hormone (GnRH) neurosecretion. Homologous neurons in laboratory animals are thought to modulate episodic GnRH secretion primarily via influencing KP receptors on the hypophysiotropic fiber projections of GnRH neurons. To explore the structural basis of this putative axo-axonal communication in humans, we analyzed the anatomical relationship of KP-immunoreactive (IR), NKB-IR and SP-IR axon plexuses with hypophysiotropic GnRH fiber projections. Immunohistochemical studies were carried out on histological samples from postmenopausal women. The neuropeptide-IR axons innervated densely the portal capillary network in the postinfundibular eminence. Subsets of the fibers formed descending tracts in the infundibular stalk, some reaching the neurohypophysis. KP-IR, NKB-IR and SP-IR plexuses intermingled, and established occasional contacts, with hypophysiotropic GnRH fibers in the postinfundibular eminence and through their lengthy course while descending within the infundibular stalk. Triple-immunofluorescent studies also revealed considerable overlap between the KP, NKB and SP signals in individual fibers, providing evidence that these peptidergic projections arise from neurons of the mediobasal hypothalamus. These neuroanatomical observations indicate that the hypophysiotropic projections of human GnRH neurons in the postinfundibular eminence and the descending GnRH tract coursing through the infundibular stalk to the neurohypophysis are exposed to neurotransmitters/neuropeptides released by dense KP-IR, NKB-IR and SP-IR fiber plexuses. Localization and characterization of axonal neuropeptide receptors will be required to clarify the putative autocrine and paracrine interactions in these anatomical regions.

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“…The 10 best-prepared brains were used for photographs, measurements, and statistical analysis. All photographs were taken parallel (6) and anterior cerebral artery (ACAJ (7); c: two preoptic arteries (8) arising from ACA; d: preoptic artery and commissural arteries; e: preoptic artery (8) and optic branch (9) of ACA; f: preoptic artery (8) and supraoptic artery (10); g: supraoptic artery (10) and optic branch (11) of internal carotid artery (ICA) (12); h: right (13) and left (13') superior hypophyseal arteries (SHAs); i: superior (13) and inferior hypophyseal arteries (cut);y. two ipsilateral SHAs (13); k: collateral branches of same SHA (13'); 1: SHA (13) and optic branch (9); m: SHA (13') and tuberoinfundibular artery (14) arising from ICA (12); n: SHA (13) and tuberoinfundibular artery (15) arising from posterior communicating artery (PCoA) (16); o: two tuberoinfundibular branches (14) of ICA; p: tuberoinfundibular branch (14) and optic branch (11) of ICA; q: tuberoinfundibular branch (14) and PCoA (16); r: tuberoinfundibular branch (14) of ICA and tuberoinfundibular branch (15) of PCoA; s: tuberoinfundibular artery (15) and optic branch (11); t: tuberoinfundibular artery (15) and PCoA (16); u: collateral branches of tuberoinfundibular artery (15); v: two ipsilateral tuberoinfundibular arteries (15); w: two contralateral tuberoinfundibular arteries; x: tuberoinfundibular artery (15) and mamillary branch (17) of PCoA; y: tuberoinfundibular artery (15) and mamillary ...…”

Section: Methodsmentioning

confidence: 99%

Microanatomy and possible clinical significance of anastomoses among hypothalamic arteries.

Marinković

Milisavljevic

Marinković

1989

Stroke

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We examined anastomoses among the hypothalamic arteries in 14 human brains using an injection technique, microdissection, and a stereoscopic microscope. Five to 22 anastomoses (mean 10.1) were found in all 14 brains on each side, varying from 20 to 280 (mean 71) /*m in diameter and from 0.1 to 5.3 (mean 1.52) mm long. A single hypothalamic artery may be connected to other vessels by one to 10 anastomoses. The anastomoses were channel-like or plexiform; both types may be ipsilateral or right-left. They connected the hypothalamic arteries "end-to-end," "end-to-side," and "side-to-side." The interconnected arteries ranged from 30 to 1,900 (mean 148) /xm in diameter. Anastomoses were most frequent among the commissural arteries and in the distribution of the superior hypophyseal arteries and the tuberoinfundibular branches of the posterior communicating artery. The largest anastomoses were found among the tuberoinfundibular branches of the posterior communicating and internal carotid arteries, as well as among the premamillary arteries and the mamillary branches. We discuss the neurologic, neuroendocrinologic, and neurosurgical significance of the described anastomoses. {Stroke 1989;20:1341-1352) M ost previous studies dealing with the anatomic examination of the hypothalamic arteries 1 -8 have only mentioned the presence of a "circuminfundibular plexus" without giving any information about the frequency, number, or size of the anastomoses within the plexus. Others 9 -12 drew special attention only to capillary connections and not to arterial anastomoses in the hypothalamopituitary region. Hence, there is an obvious lack of data concerning anastomoses among the hypothalamic arteries. These anastomoses could be of great neurologic, neuroendocrinologic, and neurosurgical significance for several reasons. Neurologists need information about the vascular pattern in the hypothalamic region to predict the risk of ischemic damage in that region following thromboembolic events and other pathologic processes that may compromise local blood flow; neurosurgeons, who perform delicate operations in the perichiasmatic, tuberal, and interpeduncular regions, must have detailed information on the hypothalamic microvasculature; and, finally, ongoing presence of Received October 17, 1988; accepted May 17, 1989. these anastomoses could be a way of locally regulating neurosecretory activity.Subjects and Methods We examined 28 sets of hypothalamic arteries in 14 brains of individuals aged 28-67 years. Each brain was carefully removed from the skull after cutting the internal carotid arteries (ICAs), optic nerves, and pituitary stalk as low as possible. Plastic catheters were placed in the basilar artery and in both ICAs. In most instances, the main stems of the middle cerebral and anterior choroidal arteries were ligated, as were the distal segments of the anterior cerebral arteries (ACAs) and the posterior cerebral arteries (PCAs). Thereafter, the components of the circle of Willis were irrigated with isotonic saline and injected wit...

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Sur la vascularisation du tuber postérieur chez l'homme et sur les relations vasculaires tubérohypophysaires

Cited by 28 publications

References 19 publications

Neuroanatomy of the Human Hypothalamic Kisspeptin System

Neuroanatomy of the Human Hypothalamic Kisspeptin System

Hypophysiotropic Gonadotropin-Releasing Hormone Projections Are Exposed to Dense Plexuses of Kisspeptin, Neurokinin B and Substance P Immunoreactive Fibers in the Human: A Study on Tissues from Postmenopausal Women

Microanatomy and possible clinical significance of anastomoses among hypothalamic arteries.

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