User:Ashbuw223/sandbox

Ideas:
>Look into Dr. Ben Trumble- From ASU- he has research on Testosterone in evolutionary terms ( https://shesc.asu.edu/people/benjamin-trumble )

>could add more to “fatherhood”

>make sure that sources aren’t biased (ex.- just looking at US men)

>clarify some explanations, layman's terms?

>Add more in terms of cultural variation and evolutionary theory

References:

 * Lombardo, et al. (2012). "Fetal Testosterone Influences Sexually Dimorphic Gray Matter in the Human Brain". The Journal of Neuroscience : The Official Journal of the Society for Neuroscience., 32 (2), 674-680.
 * Persico, et al. (2018). Analysis of Human Brain Structure Reveals that the Brain “Types” Typical of Males Are Also Typical of Females, and Vice Versa. Frontiers in Human Neuroscience.,12, Frontiers in human neuroscience., 2018, Vol.12.
 * Sobolewski, et al. (2018). Developmental exposures to ultrafine particle air pollution reduces early testosterone levels and adult male social novelty preference: Risk for children’s sex-biased neurobehavioral disorders. Neurotoxicology., 68, 203-211.

Editing:
The goal was to add some updated information about the differences between certain regions of the male and female brain. I also believe that the article could have some different vocabulary to clarify some of the ideas already stated.

Early infancy:

Early infancy androgen effects are the least understood. In the first weeks of life for male infants, testosterone levels rise. The levels remain in a pubertal range for a few months, but usually reach the barely detectable levels of childhood by 4–7 months of age. The function of this rise in humans is unknown. It has been theorized that brain masculinization is occurring since no significant changes have been identified in other parts of the body. The male brain is masculinized by the aromatization of testosterone into estrogen, which crosses the blood–brain barrier and enters the male brain, whereas female fetuses have α-fetoprotein, which binds the estrogen so that female brains are not affected. Increased levels of fetal testosterone in males during development is correlated with increased grey matter in certain regions of the brain[1]'''. The increased volume in these regions is related to the areas that grow larger in males than in females during the prepubertal stage of development. Some studies have tried to find a correlation between this growth and the increased prevalence of neurodevelopmental disorders in males compared to females. ('''use new article by baron-cohen made in another tab?)

* Note, these sections were separated by about 12 paragraphs and I felt that it was important to add this information to both of them.

Brain:

The brain is also affected by this sexual differentiation; the enzyme aromatase converts testosterone into estradiol that is responsible for masculinization of the brain in male mice. In humans, masculinization of the fetal brain appears, by observation of gender preference in patients with congenital diseases of androgen formation or androgen receptor function, to be associated with functional androgen receptors.

There are some differences between a male and female brain (possibly the result of different testosterone levels and the relative sensitivity to the hormone[2]), one of them being size: the male human brain is, on average, larger. Men were found to have a total myelinated fiber length of 176,000 km at the age of 20, whereas in women the total length was 149,000 km (approx. 15% less). '''Sexually dimorphic development of the unmyelinated fibers in certain regions of the human brain is also observed to be greater in males than in females. Most studies have been done on male rats until recently where scientists have tracked the development in males in the UK. They take samples of amniotic fluid in the womb for the hormone levels and follow up with MRI’s to see the correlation in brain volume once the males have grown. This increased volume in the region due to fetal testosterone that affects male brains has an opposite effect in females. These areas are much lower in volume in a female's brain, but there are regions with increased volumes in the female brain that remain unaffected in the male brain. Because these studies are limited, scientists can not yet attribute these traits to the differences in sex chromosomes alone.'''