1.   A new study suggests that in the laboratory roundworm, and maybe people too, youthfulness is maintained by hormonal signals from the brain.

2.   Breast development is stimulated by estrogen, which is released from the ovaries upon a hormonal signal from the pituitary gland.

3.   Could it be that aging, like puberty and menopause, is a programmed life-cycle event set off by hormonal signals from the brain?

4.   Other grafting experiments suggested that the hypothalamus was the neural recipient of the hormonal signal.

5.   Without a working hormonal signal for fullness, or satiety, a person might continue to overeat even when extreme corpulence threatens health and ego.