NR ATOR
AU Vidal,E.; Bolea,R.; Tortosa,R.; Costa,C.; Domenech,A.; Monleon,E.; Vargas,A.; Badiola,J.J.; Pumarola,M.
TI Assessment of calcium-binding proteins (Parvalbumin and Calbindin D-28K) and perineuronal nets in normal and scrapie-affected adult sheep brains
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Pathogenesis PATH-02
PT Konferenz-Poster
AB
Scrapie is a prion disease in small ruminants that manifests itself with neurological clinical signs amongst which are ataxia and tremors. These signs can be partially explained by an imbalance in central inhibitory innervation. The study of the brain's inhibitory neuronal GABAergic populations and of their extracellular matrix has been used to define, in part, the pathogenesis of human prion diseases and scrapie models in rodents.
We thoroughly characterised the brain distribution of neuronal GABAergic subpopulations using, as markers, antibodies against the calcium binding proteins parvalbumin and calbindin D-28K. By means of affinity histochemistry with Wysteria floribunda agglutinin, we then evaluated the distribution of this perineuronal net marker.
These techniques were performed on adult ovine brain; on nine scrapie-positive sheep and on four infection-free sheep. These animals had previously undergone clinical follow-up as well as a lesion profile and an immunohistochemical profile of the scrapie-associated prion protein deposition patterns in the brain.
The study of calcium-binding proteins revealed an alteration of the parvalbumin positive GABAergic neuronal subpopulation. In scrapie-positive cases, a reduction in stained neuronal perykaria was observed, along with a marked reduction of neurite labelling. This finding is remarkable in regions such as the neocortex, particularly the motor frontal cortex, and is concomitant with a moderate PrPsc deposition and a mild degree of lesion. No changes were observed in the extracellular matrix study.
The results of the present study provide a partial explanation for the mechanisms of scrapie clinical signs due to a disturbance of the parvalbumin-positive inhibitory neuronal population.
This study was partially financed by the project with reference ET2002-05168-C04-01 of the Spanish Ministry of Science and Technology (MCyT).
AD Enric Vidal, Martí Pumarola, Priocat Lab., CReSA, Universitat Autònoma de Barcelona, Spain; Martí Pumarola, BTAC, Department of Animal Medicine and Surgery, Veterinary Faculty, Universitat Autònoma de Barcelona, Spain; Raül Tortosa, Carme Costa, Anna Domènech, Martí Pumarola, Department of Animal Medicine and Surgery , Veterinary Faculty, Universitat Autònoma de Barcelona, Spain; Rosa Bolea, Eva Monleón, Antonia Vargas, Juan José Badiola, National Reference Centre for Transmissible Spongiform Encephalophaties, Veterinary Faculty, University of Zaragoza, Spain
SP englisch
PO Deutschland