[Neuronal changes induced by degenerative processes in the central nervous system. The influence of normal and pathological aging].
BACKGROUND
In the last years, an important effort has been made to know which are the causes of the neurodegenerative processes in the Central Nervous System and the morphological changes occurred under pathological situations and/or with normal ageing.


METHODS
Usually, neurodegenerative disorders have been associated with neuronal loss and reactive gliosis. However, the quantitative studies showed different or although contradictory results. These results are variable depending on the animal model, cerebral area or the technical procedure. However, there are other neuronal changes related with neurodegeneration. One of them is the presence of dark neurons. These neurons have been characterized by their strong staining and their structural and ultrastructural changes.


CONCLUSIONS
In the present work we review about these neuronal changes in the literature, and the knowledge about the quantitative changes observed in two degenerative disorders: aging and induced cerebral lesions. In this way, we study normal and pathological neurodegenerative processes.
Ramírez-Expósito
M J
MJ
Area de Fisiología, Facultad de Ciencias Experimentales, Universidad de Jaén, España. mramirez@ujaen.es
Martínez-Martos
J M
JM
D000368:Aged; D000375:Aging / Q000502:physiology*; D017209:Apoptosis / Q000502:physiology; D001921:Brain / Q000473:pathology*; D002493:Central Nervous System Diseases / Q000473:pathology*; D006801:Humans; D009336:Necrosis; D009410:Nerve Degeneration / Q000473:pathology*; D019636:Neurodegenerative Diseases / Q000473:pathology; D009474:Neurons / Q000473:pathology*