‘A marriage proves its excellence by being able to put up with an occasional exception.’ –Nietzsche


Discoveries by scientists over the past 10 years have elucidated biological sex differences in brain structure, chemistry and function. “These variations occur throughout the brain, in regions involved in language, memory, emotion, vision, hearing and navigation,” explains Larry Cahill, Ph.D., an associate professor in the Department of Neurobiology and Behavior at the University of California, Irvine.

While women and men struggle to communicate with each other and ponder why they don’t think and react to things in similar ways, science is proving that the differences in our brains may have more serious implications beyond our everyday social interactions. (…)

To better understand the implications of sex differences in the brain, it is important to examine disease entities in depth. Take Alzheimer’s disease, for example. Significant differences exist between men and women who suffer from the disease. (…)

Schizophrenia is another disease that affects men and women differently. Differences include age of onset, symptoms and the time course of the disease. In addition, structural brain differences are apparent. According to Cahill, “men with schizophrenia show significantly larger ventricles than do healthy men, whereas no such enlargement is seen in women with schizophrenia.”

Researchers do not understand the implications of these differences yet, but the study of sex differences in the brain is advancing quickly.

{ ScienceDaily | Continue reading }

There are fundamental sex differences between males and females that go well beyond reproduction. The more people look, the more differ ences are found in both the structure and function of cells throughout the brain. It’s just mind-boggling when you see the complexities. There is recent data suggesting that glial cells from male and female neonates respond differently to estrogen, as if there’s already been some programming that keeps the male glial cells from responding to estrogen the same way as the female cells. We have evidence, as do others, that the hippocampus, a memory-related organ unrelated to reproduction, responds differently to estrogens. The female responds to estrogen by forming new synaptic connections in the hippocampus, while the male does not. But if you block the actions of testosterone in the male at birth, then the male will respond to estrogens to induce these synapses. There are many other examples. The differences include cerebellum, the autonomic nervous system, cerebral cortex, and hypothalamus. The more we look, the more sex differences we discover. (…)

It’s very clear, for example, that psychotropic medications and many other drugs work differently in males and females. Some of it is related to sex differ ences in how the liver clears drugs from the body, but almost any drug that affects the brain is going to work somewhat differently in the male and female, depending on the gender first and secondly on the hormonal status. (…)

When the Women’s Health Initiative (WHI) tested Prempro, a combination of Premarin [estrogen made from horse urine] and Provera [a synthetic progestin], all it really did was to show that that’s not a very good combination.

{ Bruce McEwen interview/The Dana Foundation | Continue reading }