Monday, March 16, 2009

Which is More Precious, Male or Female Brain?

This is an interesting look at the biological differences between the male and female brain. Contrary to much of what passes for knowledge in the mainstream culture, men and women are very different in some ways, and yet the differences within each gender are greater than the differences between genders. How is that for confusing?
By News Staff | January 16th 2009 12:00 AM

Writing in the Journal of Biological Chemistry, a group of researchers found that nutrient deprivation of neurons produced sex-dependent effects. Male neurons more readily withered up and died, while female neurons did their best to conserve energy and stay alive.

That's right, nature has declared female brains should survive with a lot less than males. Take that, glass ceiling!

The idea that the sexes respond differently to nutrient depravation is not new and revolves around the male preferences to conserve protein and female preferences to conserve fat. However, these metabolic differences have really only been examined in nutrient-rich tissues like muscles, fat deposits, and the liver.

Robert Clark and colleagues at the Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center examined whether this sex-dependent response in starvation could manifest in brain cells. They grew neurons taken separately from male and female rats or mice in lab dishes and subjected them to starvation over 72 hours.

After 24 hours, the male neurons experienced significantly more cell dysfunction (measured by analyzing cell respiration, which decreased by over 70% in male cells compared to 50% in female cells) and death. Visually, male neurons also displayed more abundant signs of autophagy, whereby a cell breaks down its components as a fuel source, while female neurons created more lipid droplets to store fat reserves.

As with other cell culture studies, the researchers note these results may not be truly indicative of what happens in living animals during starvation, but it allows them to look at the neurons independent of external factors like circulating hormones.

Article: "Starving Neurons Show Sex Difference in Autophagy" by Lina Du, Robert W. Hickey, Hülya Bayır, Simon C. Watkins, Vladimir Tyurin, Fengli Guo, Patrick M. Kochanek, Larry W. Jenkins, Jin Ren, Greg Gibson, Charleen T. Chu, Valerian E. Kagan, and Robert S. B. Clark, J. Biol. Chem..2009; 284: 2383-2396
This really isn't new information in the BIG sense, although it is unique in the specific sense. We have long known that more males are conceived than females, that slightly more are born, and that by age 50 or so, there are more females. Males are biologically weaker than females when it comes to survival.

No comments: