Why a man and a woman have a different kind of brain functions? Or why the males and females behave differently during a particular incident? All these questions were asked several times by seekers but until now they never receive a proper reply. This time the University of Maryland School of Medicine (UMSOM) researchers have found the answers, which could solve the confusion.
Margaret M. McCarthy, Ph.D., who chairs the Department of Pharmacology carried out the research, which was funded by NIH, Natural Sciences and Engineering Council of Canada, Canadian Institutes of Health Research, Alberta Innovates and BranchOut Neurological Foundation. She believes that the new study could ultimately help researchers to understand behavioural development differences between males and females.
As per the associated researchers, they have discovered a mechanism for how androgens, the male sex steroids is related to brain development such as more aggression and rougher play behaviour.
McCarthy said that "We already knew that the brains of males and females are different and that testosterone produced during the second trimester in humans and late gestation in rodents contributes to the differences but we did not know how testosterone has these effects."
This new study, published in Neuron, suggests that a key contributor to the differences in play behaviour between men and women is a sex-based difference in the new-born cells in the part of the human brain, called amygdala, which is responsible for controlling emotions as well as social behaviour.
The findings showed that males have less number of these new-born cells because they are actively eliminated by immune cells. But, in the case of females, the new-born cells differentiated into a type of glial cell in the central nervous system.
In terms of males, the testosterone increased signalling at receptors in the brain that bind endocannabinoids or ECs and causes immune cells to be activated. The ECs is the key player, who prompts the immune cells to effectively eliminate the newborn cells in males.
However, the female rats, used in the study, was unaffected, which means that the activation of the immune cells by the increased ECs in males was necessary for cell elimination.
The research also showed that the use of marijuana, which stimulates ECs in the brain as well as the nervous system, could impact the brain development of the fetus. But, this impact could vary between male and female foetuses.
UMSOM Dean E. Albert Reece, MD, PhD, MBA, who is also the Executive Vice President for Medical Affairs, University of Maryland, and the John Z. and Akiko K. Bowers Distinguished Professor said "These discoveries into brain development are critical as we work to tackle brain disorders as early in life as possible, even in pregnancy."