Stress and the aging hippocampus

The "glucocorticoid cascade hypothesis" of hippocampal aging has stimulated a great deal of research into the neuroendocrine aspects of aging and the role of glucocorticoids, in particular. Besides strengthening the methods f or investigating the aging brain, this research has revealed that the inter actions between glucocorticoids and hippocampal neurons are far more compli cated than originally envisioned and involve the participation of neurotran smitter systems, particularly the excitatory amino acids, as well as calciu m ions and neurotrophins. New information has provided insights into the ro le of early experience in determining individual differences in brain and b ody aging by setting the reactivity of the hypothalamopituitary-adrenal axi s and the autonomic nervous system. As a result of this research and advanc es in neuroscience and the study of aging, we now have a far more sophistic ated view of the interactions among genes, early development, and environme ntal influences, as well as a greater appreciation of events at the cellula r and molecular levels which protect neurons, and a greater appreciation of pathways of neuronal damage and destruction. While documenting the ultimat e vulnerability of the brain to stressful challenges and to the aging proce ss, the net result of this research has highlighted the resilience of the b rain and offered new hope for treatment strategies for promoting the health of the aging brain.