Congrats to the Prevot team for this new paper shedding the light on novel puberty mechanisms! great collaboration!
https://www.nature.com/articles/s41593-021-00960-z
intro
The GnRH network is not exclusively neuronal but includes at least two glial cell types: tanycytes, which control the access of GnRH neurosecretory terminals to the pericapillary space of pituitary portal vessels, into which the hormone is released, and astrocytes, whose communication with GnRH neurons is essential for reproductive function6. Glial cells, especially astrocytes, also help generate physiological responses by forming a hub with neurons that integrates internal and external cues within the adult brain6. Additionally, they act as cartographers of synaptogenesis and neural circuit formation in the developing CNS7,8. Conversely, studies in the neocortex suggest that astrocyte formation is regulated by extrinsic signals generated by neurons, the development of which precedes gliogenesis9. We therefore asked whether GnRH neurons could themselves be responsible for the circuit formation subtending reproductive function in adulthood by establishing a glial entourage during postnatal development.
Here, we demonstrate that GnRH neurons in the infantile period attract newborn progenitor cells that differentiate into astrocytes and remain closely associated with them, essentially ‘escorting’ these neurons into adulthood. Additionally, local inhibition of infantile gliogenesis in the preoptic region, which harbors GnRH neuronal somata, delays puberty. The interaction between GnRH neurons and newborn astrocytes underlying correct sexual maturation depends on reciprocal prostaglandin-mediated signaling, and especially the expression of the prostaglandin D2 (PGD2) receptor DP1 by these newborn cells. Our findings thus identify a new neuron-to-neural-progenitor communication mechanism that unfolds during the infantile period and times the pubertal activation of the reproductive axis.