Researchers at the Maryland University Medical School have discovered a mechanism for how androgen-male sex steroids – evolve brain development to create behavioral differences, such as greater aggression and tougher gambling behavior. The research, which was published in the journal Neuron, could ultimately help us to understand the differences in behavioral development between men and women.
The study's author, Margaret M. McCarthy, said: "We already know that the brains of men and women are different and that testosterone produced in humans in the second trimester and delayed pregnancy in rodents contribute to differences, but we did not know how testosterone has these effects. "
A key factor contributing to differences in gambling behavior between men and women is a gender-based difference in the number of newborn cells in the brain called the amygdala that controls emotions and social behaviors. Research has shown that males have fewer of these newborn cells because they are actively eliminated by the immune system cells.
In females, newborn cells differentiated into one type of glial cell, the most abundant type of cells in the central nervous system. In males, however, testosterone increased signaling to receptors in the brain, which block endocannabinoids, causing immune cell activation. Endocannabinoids prompted immune cells to efficiently eliminate newborn cells in males. Female rats in the study were unaffected, suggesting that activation of the immune cells by elevated endocannabinoids in males was necessary to eliminate the cells. In this regard, this research shows that the use of cannabis, which stimulates endocannavinoids in the brain and the nervous system, could affect the development of the fetus brain and this effect could be different between male and female embryos .
This study provides a mechanism for differences in gender-based social behaviors and suggests that differences in androgen and endocannabinoid signaling can contribute to individual differences in brain development and hence in behavioral differences between humans.