Scientists have long known of dissimilarities in anatomy and activity between the brains of women and men—now a rodent study shows that even individual neurons behave differently depending on sex.

Robert Clark of the University of Pittsburgh School of Medicine and his colleagues found that cultured neurons from female rats and mice survived longer than did neurons from their male counterparts when facing starvation. Such sex differences had been evident for decades in other body tissues, but so far no one had looked at brain cells, Clark says. When he and his team deprived the cells of nutrients, female neurons consumed mainly fat resources to stay alive, whereas large amounts of male cells started to eat up their own protein-based building blocks—and subsequently died.

The findings suggest that tailoring nutrition to a patient’s gender during critical care—for example, after illnesses that temporarily cut off the brain’s nutrient supply, such as stroke—might help prevent brain cell death, Clark posits. Men’s neurons might fare better on a high-protein diet, for instance, whereas high fat content would probably nourish women’s brain cells best, he adds.

Self-cannibalism makes sense for body tissues other than the brain, but why male neurons engaged in it to such a large extent is a mystery, Clark says. “You can understand why during famine, you would want to break down muscle to preserve the rest of your body, but it’s harder to understand why you would want to break down proteins within your brain.”

Note: This article was originally printed with the title, "Neuron Cannibalism."

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