14 DAY TRIAL // Scientists wondered why is it that women tend to be more anxious than men, and they found out that a possible cause might be the level of testosterone.
Florida State University researcher and associate professor in the College of Medicine, Mohamed Kabbaj, was recently awarded a five-year $1.8 million grant from the National Institute of Mental Health, to carry out a research on sex differences in anxiety.
After beginning the investigation, the researchers decided to also work on the role of a gene called zif268.
Kabbaj says that “it's a very important molecule,” and studies have shown that “so far, zif268 plays a major role in learning, memory and drug addiction.
“I think our work shows for the first time that it's also implicated in anxiety.”
For this research, males and females rats were exposed to situations that cause anxiety, and their brains were studied to see how did the zif268 gene had reacted.
The results were quite surprising as they did not expect to find a difference in gene expression between males and females in only one part of the brain.
The difference appeared in the medial prefrontal cortex, the part of the brain that allows humans to experience emotions as well as the meaning of things.
“We were not expecting to see that, so we wanted to follow up with functional studies to see if this difference between males and females has any significance in terms of anxiety and difference in social interaction,” Kabbaj said.
Because males have more zif268 in their prefrontal cortex, they are also less anxious than females, so when scientists experimented and reduced the expression of the gene in the prefrontal cortex of males, they became as anxious as females.
Kabbaj says that “one of the questions you have to ask is why males have more zif than females.
“We think it's because of testosterone, [as] testosterone is keeping that level of zif very high.
He added that “recent findings show that the hormone estrogen is not implicated in sex differences in anxiety, however, preliminary data show the male hormone testosterone may be protecting male rats from developing anxiety.
“The fact that females do not have a lot of testosterone may put them at risk of developing anxiety disorders.”
The researchers believe that if they could prove the role of the gene in anxity, then they could design drugs that could reduce anxiety in women.
“If we increase zif expression in men that have some level of depression or anxiety, maybe we can help them, too,” concluded Kabbaj.