INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
artículos
Título:
Dopaminergic mesencephalic systems and motor performance in very old rats
Autor/es:
SANCHEZ HL; SILVA LB; PORTIANSKY EL; HEREÑU CB; GOYA RG
Revista:
NEUROSCIENCE
Editorial:
Elsevier
Referencias:
Lugar: USA; Año: 2008 vol. 154 p. 1598 - 1606
ISSN:
0306-4522
Resumen:
ABSTRACT                                      Morphologic and functional studies describing the impact of aging on mesencephalic dopaminergic (DA) neurons in laboratory animals are rather scanty and inconclusive.  In rats, stereological studies characterizing age changes in the mesencephalic DA neurons have not been documented. In order to fill this information gap and to determine whether the very old rat may serve as a suitable animal model of Parkinson’s disease, we performed a stereological assessment of the mesencephalic tyrosine hydroxylase immunoreactive (TH-ir) neurons in young-adult (4-6 mo.), old (22-24 mo.) and senile (30-32 mo.) Sprague Dawley female rats. Age changes in motor performance were also assessed measuring the endurance of rats to hang from a wire mesh pole or to remain on a ramp set at different angles to the floor. Morphometric analysis of the TH-ir neurons of the substantia nigra (SN) and ventral tegmental area (VTA) was performed using an appropriate image analysis system. We observed a significant age-related reduction in TH-ir neuron numbers in the SN (17 and 33% reduction in old and senile rats, respectively compared with young counterparts) but not in the VTA. The size of the TH-ir cells increased significantly in both the SN and VTA of the senescent animals but TH labelling intensity fell. Motor performance deteriorated markedly in the old and senile rats as compared with young animals. These findings reveal the existence of a moderate but significant vulneralbility of mesencephalic DA neurons to aging in rats. This phenomenon, which is particularly marked in the SN of very old rats, may contribute to the age-related deterioration of motor performance recorded in this species.