title: [Aging and neurodegeneration: molecular and cellular bases].
abstract: OBJECTIVE
  A review about the possible cellular and molecular mechanisms of aging and related neurodegenerative diseases.
  
  
  METHODS
  The mechanisms involved in neuronal decrease, connectivity losses and glial reactivity, detected both in neurodegenerative (Alzheimer's disease) and physiological aging, are analyzed from the morphological and histological point of view to provide the morphofunctional base of the cognitive and intellectual alterations characterizing the senescence process. Taken together, these data are correlated to the possible genetical aspects implied in this process, reviewing the most relevant results on senescence and cellular death obtained from yeast, fruit fly and nematodes; besides this, a brief review of the molecular biology of gerontogenes was carried out, and the possible mechanisms inducing aging and neurodegenerative processes are analyzed according to the state-of-the-art related theories. Finally, cellular, biochemical and genetical data are correlated in the signal transduction way implied in the increase of the intracellular calcium level as the starting point of cell death.
  
  
  CONCLUSIONS
  The main process implied in the neuronal cell death responsible for aging and the related neurodegenerative diseases are started by different agents such as the lacking of neurotrophic factors, hypoxia, hypoglycemia, excitotoxicity, and oxygen and nitrogen free radicals.
authors.affiliation: Unidad Asociada CSIC-Universidad de Jaén, Areas de Biología Celular y Bioquímica y Biología Molecular, Departamento de Neuroanatomía Comparada, Madrid, España. apeinado@ujaen.es
authors.forename: M A
authors.initials: MA
authors.lastname: Peinado
authors.forename: M L
authors.initials: ML
authors.lastname: del Moral
authors.forename: F J
authors.initials: FJ
authors.lastname: Esteban
authors.forename: E
authors.initials: E
authors.lastname: Martínez-Lara
authors.forename: E
authors.initials: E
authors.lastname: Siles
authors.forename: A
authors.initials: A
authors.lastname: Jiménez
authors.forename: R
authors.initials: R
authors.lastname: Hernández-Cobo
authors.forename: S
authors.initials: S
authors.lastname: Blanco
authors.forename: J
authors.initials: J
authors.lastname: Rodrigo
authors.forename: J A
authors.initials: JA
authors.lastname: Pedrosa
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D017209:Apoptosis; D001921:Brain / Q000166:cytology / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D016923:Cell Death; D004734:Energy Metabolism; D005609:Free Radicals; D006487:Hemostasis; D006801:Humans; D019636:Neurodegenerative Diseases / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D009569:Nitric Oxide / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology; D017470:Receptors, Glutamate
chemical_list: D005609:Free Radicals; D017470:Receptors, Glutamate; D009569:Nitric Oxide; D002118:Calcium