Effects of neonatal hypoxia-ischemia on cerebellar glutamatergic and GABAergic cell populations in the rat

BENITEZ SG; CASTRO AE; PATTERSON SI; MUÑOZ EM; SELTZER, AM

Huerta Grande. Córdoba. Argentina

Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2013

Sociedad Argentina de Investigaciones en Neurociencias

Premature birth and/or hypoxia-ischemia (HI) in the perinatal period are among the risk factors for cerebellar pathologies. The characterization of neonatal brain reactions to injury is of great importance in order to understand endogenous repair and survival strategies. We assessed the effects of HI on the postnatal developing cerebellum by studying the expression of NeuroD1 and GAD67 in glutamatergic and GABAergic neurons, respectively, via immunohistochemistry (IHC) and Western blot (WB). The treatment was performed at postnatal day 8 (P8) with sampling at P15. We detected a significant decrease of NeuroD1(+)-migrating cells in the molecular layer (ML) of lesioned (L) cerebella, which may be associated with abnormalities observed in radial glial fibers. These effects were accompanied by a reduction in the number of cells in the internal granular layer (IGL). A substantial change in the number, morphology and spatial orientation of Purkinje cells was also observed. Atypical cells displayed altered features; such as less-developed dendritic arborization towards the ML, mis-orientation, and smaller nuclei stained intensely with propidium iodide, indicating high chromatin compaction. In agreement with the IHC results, quantifications by WB showed significantly diminished NeuroD1 and GAD67 levels in the L group. In conclusion, we hypothesize that these changes could be related to mechanisms of adaptation to the lack of oxygen during a crucial moment in cerebellar development. (Libro de Resúmenes pp315)