I have a few more thoughts that need to be known about this then I will be done on this topic.
Mast Cells in the Developing Brain Determine Adult Sexual Behavior
Steroid hormones are the principal drivers of brain sexual differentiation. There has been a long-standing assumption that hormones act largely upon neurons because they express steroid receptors at high levels. We here demonstrate that sex-specific organization of the POA and resultant male-typical sexual behavior depends upon a surprising cellular player, the mast cell. Mast cells populate the brains of many species, including humans (Georgin-Lavialle et al., 2016), but the possibility that mast cells are important to human brain development was discounted due to their sparseness. This warrants revisiting given our observation that a very small number of mast cells powerfully shape lifelong sex-specific endpoints in brain morphology and behavior.
Our data indicate that mast cells basally contribute to the masculinization process in males because mast cell inhibition decreased male-typical sexual behavior in adulthood. Likewise, pharmacologically induced increases in mast cell activation in females affects female sexual differentiation, shifting females toward a male-typical organization of the POA that is life-long and corresponds with increases in male-typical sociosexual behaviors. We further identified histamine as a mast-cell-derived mediator that induces masculinization of microglia and dendritic spine endpoints and likely affects the masculinization process by stimulating microglia to release PGE2, which we have previously identified as the major molecular signal driving masculinization of the POA and male-typical sexual behavior
I also meant to link it with this,