Testosterone kills brain cells

From a 27 September 2006 AP article:

Tests on brain cells in lab dishes showed that while a little of the male hormone is good, too much of it causes cells to self-destruct in a process similar to that seen in brain illnesses such as Alzheimer's.

"Too little testosterone is bad, too much is bad but the right amount is perfect," said Barbara Ehrlich of Yale University in Connecticut, who led the study.

...

Ehrlich's team tried the same thing with the "female" hormone estrogen, just to be fair.

"We were surprised, but it actually looks like estrogen is neuroprotective. If anything, there is less cell death in the presence of estrogen," she said.