Seed: The Reinvention of Self, about how stress can limit the growth of neurons.
The realization that typical laboratory conditions are debilitating for animals has been one of the accidental discoveries of the neurogenesis field. Nottebohm, for example, only witnessed neurogenesis in birds because he studied them in their actual habitat. Had he kept his finches and canaries in metal cages, depriving them of their natural social context, he would never have observed such an abundance of new cells. The birds would have been too stressed to sing. As Nottebohm has said, "Take nature away and all your insight is in a biological vacuum."
Yup. That general principle is true even for much less complex organisms. For example, people working with single-celled critters (E. coli, yeast) tend to think of exponential growth (when the cells are constantly dividing) as "normal" and observe things under those conditions. However, exponential growth in liquid culture is really, really different from most natural growth. Certainly, lessons taken from exponentially growing cells might not apply at all to cells in your body that stopped dividing before you were born.
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