Modulatory role of myelin-associated glycoprotein (MAG) on postnatal development of the cerebellum.

ANABELA PALANDRI; MATTALLONI, MARA S.; ANA VIVINETTO; PABLO LOPEZ

BS AS

Congreso; FALAN CONGRESS; 2016

Myelin-associated glycoprotein (MAG) is a minor constituent of the nervous system myelin. The role of MAG is not limited only to the process of myelination, it could also trigger signaling events with great impact on neuron survival. The cerebellar cortex is a very suitable model to study the factors that controls neuronal differentiation and apoptosis due to the spatial-temporal organization process of neurodevelopment as well as to the presence of diferent types of cells which are stratified within the gray matter of the cerebellum. Cerebellar cortex consists of three layers: the internal granular layer containing granule cells (CGN); a monolayer of Purkinje cells (Pkn) and Bergman glia. The aim of the this study was to evaluate the impact of myelination process on postnatal neurodevelopment and to characterized the involvement of MAG on neuronal differentiation process in the cerebellum, which occurs during the early postnatal period. Treatment with mAb 513 (anti-MAG antibody) showed impaired development of the cerebellar cortex, characterized by the presence of an increase in the number of CGN and Pkn cells during P31.Fluoro Jade C staining, a marker specific of neurodegeneration, showed an increase in the number of dying neurons in CGI. Finally immunostaining analysis against cell proliferation identified the presence of BrdU positive cells in the region of the CGI, suggesting increased proliferation of CGN. Together these results suggest changes in development (PKN and CGN cells), which could be due to an increase in the rate of prior proliferation during their differentiation, or alternatively to defects in the process of programmed cell death that characterizes its development.