The Hypothalamic Neuropeptide Oxytocin Is Required for Formation of the Neurovascular Interface of the Pituitary

Gutnick, Amos; Blechman, Janna; Kaslin, Jan; Herwig, Lukas; Belting, Heinz‐Georg; Affolter, Markus; Bonkowsky, Joshua L.; Levkowitz, Gil

doi:10.1016/j.devcel.2011.09.004

Cited by 59 publications

(70 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To examine the possibility of an AgRP2 neurovascular connection in the hypophysis, we crossed agrp2 :mCherry with Tg( kdrl :EGFP) S843 fish (which expresses EGFP in vascular endothelial cells47). Examination of transgene expression in this cross showed that AgRP2 terminals are juxtaposed with vessels that have been designated as the hypophysial artery42 (Fig. 3f,g).…”

Section: Resultsmentioning

confidence: 98%

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Shainer

Buchshtab

Hawkins

et al. 2017

Sci Rep

View full text Add to dashboard Cite

The neuropeptide agouti-related protein (AgRP) is expressed in the arcuate nucleus of the mammalian hypothalamus and plays a key role in regulating food consumption and energy homeostasis. Fish express two agrp genes in the brain: agrp1, considered functionally homologous with the mammalian AgRP, and agrp2. The role of agrp2 and its relationship to agrp1 are not fully understood. Utilizing BAC transgenesis, we generated transgenic zebrafish in which agrp1- and agrp2-expressing cells can be visualized and manipulated. By characterizing these transgenic lines, we showed that agrp1-expressing neurons are located in the ventral periventricular hypothalamus (the equivalent of the mammalian arcuate nucleus), projecting throughout the hypothalamus and towards the preoptic area. The agrp2 gene was expressed in the pineal gland in a previously uncharacterized subgroup of cells. Additionally, agrp2 was expressed in a small group of neurons in the preoptic area that project directly towards the pituitary and form an interface with the pituitary vasculature, suggesting that preoptic AgRP2 neurons are hypophysiotropic. We showed that direct synaptic connection can exist between AgRP1 and AgRP2 neurons in the hypothalamus, suggesting communication and coordination between AgRP1 and AgRP2 neurons and, therefore, probably also between the processes they regulate.

show abstract

Section: Resultsmentioning

confidence: 98%

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Shainer

Buchshtab

Hawkins

et al. 2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…These neurons reside in the ancestral preoptic nucleus (PON; Diepen, 1962; Figure 1), which became recently a subject of genetic studies, using transgenic fish models (Gutnick et al, 2011; Herget et al, 2013). Magnocellular neurons of adult Anamnia are quite randomly distributed within the PON, existing intermingled with other types of cells.…”

Section: Introductionmentioning

confidence: 99%

Evolution of oxytocin pathways in the brain of vertebrates

Knobloch

Grinevich

2014

Front. Behav. Neurosci.

214

168

View full text Add to dashboard Cite

The central oxytocin system transformed tremendously during the evolution, thereby adapting to the expanding properties of species. In more basal vertebrates (paraphyletic taxon Anamnia, which includes agnathans, fish and amphibians), magnocellular neurosecretory neurons producing homologs of oxytocin reside in the wall of the third ventricle of the hypothalamus composing a single hypothalamic structure, the preoptic nucleus. This nucleus further diverged in advanced vertebrates (monophyletic taxon Amniota, which includes reptiles, birds, and mammals) into the paraventricular and supraoptic nuclei with accessory nuclei (AN) between them. The individual magnocellular neurons underwent a process of transformation from primitive uni- or bipolar neurons into highly differentiated neurons. Due to these microanatomical and cytological changes, the ancient release modes of oxytocin into the cerebrospinal fluid were largely replaced by vascular release. However, the most fascinating feature of the progressive transformations of the oxytocin system has been the expansion of oxytocin axonal projections to forebrain regions. In the present review we provide a background on these evolutionary advancements. Furthermore, we draw attention to the non-synaptic axonal release in small and defined brain regions with the aim to clearly distinguish this way of oxytocin action from the classical synaptic transmission on one side and from dendritic release followed by a global diffusion on the other side. Finally, we will summarize the effects of oxytocin and its homologs on pro-social reproductive behaviors in representatives of the phylogenetic tree and will propose anatomically plausible pathways of oxytocin release contributing to these behaviors in basal vertebrates and amniots.

show abstract

“…Once at the NH, however, H-NH axons play a crucial role in shaping NH vasculature. Studies in zebrafish show that the neurotransmitter Oxytocin-like (referred to as Oxytocin), released by neurohypophyseal nerve endings, can promote vessel growth (Gutnick et al, 2011). Nevertheless, it remains unclear whether other factors operate alongside Oxytocin, potentially contributing to the H-NH vascularisation profile.…”

Section: Introductionmentioning

confidence: 99%

Direct and indirect roles of Fgf3 and Fgf10 in innervation and vascularisation of the vertebrate hypothalamic neurohypophysis

et al. 2013

View full text Add to dashboard Cite

The neurohypophysis is a crucial component of the hypothalamo-pituitary axis, serving as the site of release of hypothalamic neurohormones into a plexus of hypophyseal capillaries. The growth of hypothalamic axons and capillaries to the forming neurohypophysis in embryogenesis is therefore crucial to future adult homeostasis. Using ex vivo analyses in chick and in vivo analyses in mutant and transgenic zebrafish, we show that Fgf10 and Fgf3 secreted from the forming neurohypophysis exert direct guidance effects on hypothalamic neurosecretory axons. Simultaneously, they promote hypophyseal vascularisation, exerting early direct effects on endothelial cells that are subsequently complemented by indirect effects. Together, our studies suggest a model for the integrated neurohemal wiring of the hypothalamo-neurohypophyseal axis.

show abstract

The Hypothalamic Neuropeptide Oxytocin Is Required for Formation of the Neurovascular Interface of the Pituitary

Cited by 59 publications

References 60 publications

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Evolution of oxytocin pathways in the brain of vertebrates

Direct and indirect roles of Fgf3 and Fgf10 in innervation and vascularisation of the vertebrate hypothalamic neurohypophysis

Contact Info

Product

Resources

About