The trouble with animal models
One day in the 1950s, Stanley Cohen placed a small piece of mouse salivary gland in culture next to a ganglion. When he returned, he found massive nerve growth.
By chance, Cohen had grabbed a male mouse for the experiment. Cells in its salivary glands are 10 times more androgen-responsive than those in females. Cohen has said that if he had used a female the response would have been much less, and he wonders if he would have made the crucial association that led to the identification of nerve growth factor - and ultimately to his sharing the 1986 Nobel Prize in Physiology or Medicine.
Half a century later, a research team at the University of California, Los Angeles, looked at the expression of 23,000 genes in brain, liver, fat, and muscle tissue in mice. "We saw striking ...
