The body’s “fountain of youth” could be in the hypothalamus, an important part of the brain for emotional regulation:
For the role the hypothalamus plays in emotions see here: http://www.preservearticles.com/201104185522/role-of-hypothalamus-in-emotion.html
Part of my graduate work was tying together the soft science of yoga with the hard science of neuro-endocrinology. My thesis was that breathwork could result in stimulating the various endocrine glands to secrete the necessary hormones for re-starting brain growth in regions like the hypothalamus and amygdala, which are responsible for emotion. Additionally, as many people, including Leonard Orr and Jim Leonard postulated, emotional integration helps one live longer, theorizing correctly that negative emotions (and the related stress hormones like cortisol) are what actually kill us.
In the yogic tradition the location of the hypothalamus coincides with what is known as bindu visarga. From that point emanates amrita, which is roughly translated as the nectar of immortality. It is considered that it flows downward from that point and gets consumed by the digestive system. Certain techniques, usually involving inverted body position, reverse the flow of amrita, which can than get assimilated by the body.
Myron Stoloroff also talked about the deep connection between emotional healing and a life of vitality in his book Thanatos to Eros.