Close Juxtapositions between LHRH Immunoreactive Neurons and Substance P Immunoreactive Axons in the Human Diencephalon

Dudás, Bertalan; Merchenthaler, Istvån

doi:10.1210/jcem.87.6.8558

Cited by 29 publications

(15 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The hypothalamic distribution of GnRH-IR [44,51,52], KP-IR [7,8], NKB-IR [7] and SP-IR [30,43] neuronal cell bodies and fibers was in agreement with previous reports. While the dual-labeling experiments confirmed that GnRH neurons in the mediobasal hypothalamus receive axo-somatic and axo-dendritic afferent contacts from KP-IR, NKB-IR and SP-IR neurons [7,26,30], the present study focused on the anatomical sites of major hypophysiotropic GnRH fiber projections.…”

Section: Resultssupporting

confidence: 91%

“…While the dual-labeling experiments confirmed that GnRH neurons in the mediobasal hypothalamus receive axo-somatic and axo-dendritic afferent contacts from KP-IR, NKB-IR and SP-IR neurons [7,26,30], the present study focused on the anatomical sites of major hypophysiotropic GnRH fiber projections. These GnRH projections were present in highest abundance in the postinfundibular eminence (fig.…”

Section: Resultsmentioning

confidence: 70%

“…In the human mediobasal hypothalamus, many SP-IR neurons are identical with KP and NKB neurons [10]. SP neurons provide axo-somatic and axo-dendritic inputs to GnRH neurons, as indicated by light microscopic immunohistochemical observations in humans [30] and immunoelectronmicroscopic data from rats [31]. …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

View full text Add to dashboard Cite

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.

show abstract

Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 70%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

show abstract

“…It harbors cells releasing luteinic hormone-releasing hormone (29). In humans, these cells develop from the migrating neuroblasts of olfactory mucosa (30) and mediate estrogen feedback (31).…”

Section: Discussionmentioning

confidence: 99%

Brain response to putative pheromones in homosexual men

Savić

Berglund

Lindström

2005

Proc. Natl. Acad. Sci. U.S.A.

283

196

View full text Add to dashboard Cite

The testosterone derivative 4,16-androstadien-3-one (AND) and the estrogen-like steroid estra-1,3,5(10),16-tetraen-3-ol (EST) are candidate compounds for human pheromones. AND is detected primarily in male sweat, whereas EST has been found in female urine. In a previous positron emission tomography study, we found that smelling AND and EST activated regions covering sexually dimorphic nuclei of the anterior hypothalamus, and that this activation was differentiated with respect to sex and compound. In the present study, the pattern of activation induced by AND and EST was compared among homosexual men, heterosexual men, and heterosexual women. In contrast to heterosexual men, and in congruence with heterosexual women, homosexual men displayed hypothalamic activation in response to AND. Maximal activation was observed in the medial preoptic area͞anterior hypothalamus, which, according to animal studies, is highly involved in sexual behavior. As opposed to putative pheromones, common odors were processed similarly in all three groups of subjects and engaged only the olfactory brain (amygdala, piriform, orbitofrontal, and insular cortex). These findings show that our brain reacts differently to the two putative pheromones compared with common odors, and suggest a link between sexual orientation and hypothalamic neuronal processes.olfaction ͉ positron emission tomography ͉ hypothalamus ͉ homosexual males A ccording to animal studies, the choice of sexual partner is highly influenced by sex-specific pheromone signals, which are processed by male and female mating centers located in the anterior hypothalamus (1-3). A lesion of the respective mating center, as well as impairment of pheromone transduction, may alter the coital approach in a sex-specific way (3, 4).In a majority of animals, pheromone signals are transferred to the hypothalamus from the vomeronasal organ via the accessory olfactory nerve (5). Because our vomeronasal pit lacks neuronal connections to the brain (5, 6), the occurrence of pheromone transduction has long been questioned in humans. Several recent observations, however, suggest that this type of chemical communication cannot be ruled out. Sex steroid-derived compounds such as 4,16-androstadien-3-one (AND) and, less consistently, estra-1,3,5(10),16-tetraen-3-ol (EST) have been reported to induce sexspecific effects on the autonomic nervous system, mood, and context-dependent sexual arousal (7-12). The exact effects of AND and EST vary with the administered dose and experimental design, but, nevertheless, they seem to be sex-differentiated (especially with respect to AND), and thus to differ from the effects of ordinary odors. Studies with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have shown that smelling both AND and of EST activates the human brain (13-15), even in nonodorous concentrations (14,15). AND is a derivative of testosterone and is primarily produced in male sweat (16), whereas EST is an estrogen-resembling steroid that has been detected in the ...

show abstract

“…SP or NPK neurons project their fibers to hypothalamic areas such as the medial preoptic area [31,32], paraventricular nucleus [33] and ARC in rats [34]. SP-immunoreactive fibers were found in GnRH neurons in humans and rats [35,36]. Earlier studies have demonstrated that Tac1 products such as SP and NPK stimulated [37,38], suppressed [39,40] or did not affect LH secretion in rats.…”

mentioning

confidence: 96%

Involvement of Neurokinin Receptors in the Control of Pulsatile Luteinizing Hormone Secretion in Rats

et al. 2011

View full text Add to dashboard Cite

Abstract. It has recently been shown that neurokinin B, a tachykinin, is associated with GnRH pulse generation in sheep and goats. The aim of the present study was to clarify the role of tachykinin receptors in the control of LH secretion in rats. To this end, we evaluated the effect of CS-003, an antagonist for all three neurokinin receptors (NK1, NK2 and NK3 receptors), on pulsatile LH secretion in both sexes of rats with different routes of administration. Both oral and third ventricular administration of CS-003 suppressed LH secretion in both sexes of gonadectomized animals. Furthermore, intact male rats with oral administration of CS-003 showed decreased serum testosterone levels, which might be due to suppressed LH secretion. None of the three subtype-specific neurokinin receptor antagonists showed a significant effect on LH secretion in ovariectomized rats when each antagonist was singly administered. The present results suggest that neurokinins play a role in the control of pulsatile GnRH/LH secretion via multiple neurokinin receptors in both male and female rats. Key words: Luteinizing hormone, Neurokinin, Rat, Receptor (J. Reprod. Dev. 57: [409][410][411][412][413][414][415] 2011) ulsatile gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release is indispensable for regulation of gonadal functions, such as folliculogenesis, spermatogenesis and steroidogenesis, in rodents [1], ruminants [2,3] and primates [4]. The mechanism generating GnRH/LH pulses, called the GnRH pulse generator, has been suggested to be localized in the hypothalamus [5]. Recent studies have revealed that kisspeptin neurons located in the hypothalamus play a central role in regulating GnRH release [6,7]. Kisspeptin neurons have two populations in the hypothalamus [8]: One is located in the hypothalamic arcuate nucleus (ARC), and the other is located in the anteroventral periventricular nucleus (AVPV). Of these two populations, the AVPV kisspeptin neurons have been reported to be involved in the regulation of GnRH/LH surge [9,10]. On the other hand, the role of ARC kisspeptin neurons is still unclear, but several lines of evidence suggest that the population is associated with GnRH pulse generation [11].Recent studies have shown an interesting and essential aspect of the ARC kisspeptin neurons. Most kisspeptin neurons have neurokinin B (NKB) and dynorphin (Dyn) in sheep [12], goats [13] and rodents [14], and thus the neurons have been called KNDy neurons [15]. Colocalization of those three neuropeptides in the ARC neurons might be associated with GnRH pulse generation. It has recently been reported that mutations of genes encoding NKB and its receptor are associated with gonadotropin deficiency in humans [16], and central administration of a selective NKB receptor agonist stimulates LH secretion in sheep [17] and monkeys [18]. These reports indicate the significance of NKB/NK3 signaling in GnRH/gonadotropin release in these animal species. In addition to neurokinin B, nor-BNI, a κ-opioid receptor antagonist (KOR), rev...

show abstract

Close Juxtapositions between LHRH Immunoreactive Neurons and Substance P Immunoreactive Axons in the Human Diencephalon

Cited by 29 publications

References 38 publications

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

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

Brain response to putative pheromones in homosexual men

Involvement of Neurokinin Receptors in the Control of Pulsatile Luteinizing Hormone Secretion in Rats

Contact Info

Product

Resources

About