INVESTIGADORES
DE NICOLA Alejandro Federico
artículos
Título:
Progesterone effects on neuronal ultrastructure and expression of Microtubule-Associated Protein 2 (MAP2) in rats with acute spinal cord injury
Autor/es:
GONZALEZ, S.L.; LÓPEZ COSTA, J.J.; LABOMBARDA, M.F. ; GONZALEZ DENISELLE, M.C.; GUENNOUN, R.; SCHUMACHER, M.; DE NICOLA, A.F
Revista:
CELLULAR AND MOLECULAR NEUROBIOLOGY.
Editorial:
Springer
Referencias:
Lugar: New York; Año: 2009 vol. 29 p. 27 - 39
ISSN:
0272-4340
Resumen:
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1. Following acute spinal cord
injury, progesterone modulates several molecules essential for motoneuron
function, although the morphological substrates for these effects are unknown.
2. The present study analyzed
morphological changes in motoneurons distal to the lesion site from rats with
or without progesterone treatment. We employed electron microscopy to study
changes in nucleus and cytoplasm and immunohistochemistry for the microtubule-associated
protein 2 (MAP2) for changes in cytoskeleton.
3. After spinal cord injury, the
nucleoplasm appeared more finely dispersed resulting in reduced electron
opacity and the nucleus adopted an eccentric position. Changes of perikarya
included dissolution of Nissl bodies and dissociation of polyribosomes
(chromatolysis). After progesterone treatment for 3 days, the deafferented
motoneurons now presented a clumped nucleoplasm, a better-preserved rough
endoplasmic reticulum and absence of chromatolysis. Progesterone partially
prevented development of nuclear eccentricity. Whereas 50% of injured
motoneurons showed nuclear eccentricity, only 16% presented this phenotype
after receiving progesterone. Additionally, injured rats showed reduced
immunostaining for MAP2 in dendrites, pointing to cytoskeleton abnormalities,
whereas progesterone treatment attenuated the injury-induced loss of MAP2.
4. Our data indicated that
progesterone maintained in part neuronal ultrastructure, attenuated
chromatolysis, and preclude the loss of MAP2, suggesting a protective effect
during the early phases of spinal cord injury.
