In the animal nervous system, a very high metabolic turnover, fragile but steep ionic gradients, and morphological and structural constraints - dictated by the necessity for prompt neuronal transmission of electrical impulses and necessary plasticity - result in a highly fragile organ system. Here, we address a small sampling of major constituents of neural function at the cellular and molecular level that play important roles in development and aging, two endogenous processes that embody features of allostasis or the dynamic shifts in set points for specific homeostatic mechanisms associated with development and aging. These chapters stress the dynamic features of neuronal responses to internal (developmental) cues or the more harmful external events (injury and disease) in a modern perspective. TOC:NEUROTROPHINS AND CENTRAL NERVOUS SYSTEM DEVELOPMENT - D. B. Pereira and M. V. Chao.- NERVE GROWTH FACTOR REGULATED GENE EXPRESSION - L. A. Greene and J. M. Angelastro.- MYELINATING CELLS IN THE CENTRAL NERVOUS SYSTEM-DEVELOPMENT, AGING, AND DISEASE - J. Neman and J. de Vellis.- SULFUR-CONTAINING AMINO ACIDS IN THE CNS: HOMOCYSTEINE - D. K. Rassin.- STRESS RESPONSE SIGNAL TRANSDUCTION - X. Hu and J. R. Perez-Polo.- AGING AND OXIDATIVE STRESS RESPONSE IN THE CNS - V. Calabrese, D. A. Butterfield, and A. M. G. Stella.- PARALLELS BETWEEN NEURODEVELOPMENT AND NEURODEGENERATION: A CASE STUDY OF ALZHEIMER'S DISEASE - X. Zhu, G. Casadesus, K. M. Webber, C. S. Atwood, R. L. Bowen, G. Perry, and M. A. Smith.- DIFFERENTIATION AND DE-DIFFERENTIATION-NEURONAL CELL-CYCLE REGULATION DURING DEVELOPMENT AND AGE-RELATED NEURODEGENERATIVE DISORDERS - T. Arendt.- mRNA MODULATIONS IN STRESS AND AGING - E. Meshorer and H. Soreq.- MOLECULAR MECHANISMS OF DENDRITIC SPINE PLASTICITY IN DEVELOPMENT AND AGING - M. R. Kreutz, I. König, M. Mikhaylova, C. Spilker, and W. Zuschratter.- ALZHEIMER'S DISEASE BACE PROTEASES - S. Roßner and S. F. Lichtenthaler.- PROTEIN MISFOLDING, A COMMON MECHANISM IN THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES - L. Vergara, K. Abid, and C. Soto.- ANTI-AGING STRATEGIES - J. A. Joseph and J. R. Perez-Polo In the animal nervous system, a very high metabolic turnover, fragile but steep ionic gradients, and morphological and structural constraints - dictated by the necessity for prompt neuronal transmission of electrical impulses and necessary plasticity - result in a highly fragile organ system.