@nadel
"Perhaps now would be a reasonable time to raise questions brought up by the personal histories published so far."

I appreciate the invitation! I'm still thinking about this bit of the Gyuri Buzsaki episode:

"What make the hippocampus special is the granule cell. There is no such cell type in the neocortex. Granule cells keep dividing postnatally and the only cell type known whose life depends on circulating hormones (steroids)."

I've found a few interesting links, including:

Estrogen modulates place learning through estrogen receptors in the hippocampus - Lilia Zurkovsky 2006
(Where they implanted the hormones directly into the rat hippocampus...)

Estrogen Receptors, the Hippocampus, and Memory - Linda A. Bean 2014
(Where they used receptor knockout mice and viral vector delivery of different estrogen receptors to modify the sensitivity to estrogen.)

Do you know of anyone studying this in humans? I guess it would be difficult, since as I (barely and maybe wrongly) understand things, our estradiol level above the blood-brain barrier is higher and poorly correlated with the testable levels circulating below there. And hippocampal E2 is mostly created in the hippocampus itself...

Neurosteroids in Adult Hippocampus of Male and Female Rodents: Biosynthesis and Actions of Sex Steroids - Yasushi Hojo 2018
https://www.frontiersin.org/articles/10.3389/fendo.2018.00183/full

"Penetration of plasma E2 into the hippocampus, however, is not able to account for the level of hippocampal E2 because hippocampal E2 is much higher than that in plasma."

This graphic is fascinating:
https://www.frontiersin.org/files/Articles/357380/fendo-09-00183-HTML-r1/image_m/fendo-09-00183-g001.jpg

Would love to hear anyone's thoughts on the influence of estrogen on spatial awareness and memory!

#hippocampus #estrogen #estradiol #neurosteroids #biosynthesis #GranuleCell