PERSONAL DE APOYO
VILCHEZ ARUANI Juan
GABAB2 en el cerebelo postnatal de rata
VAZQUEZ, ELENA; VILCHEZ ARUANI, JUAN; MUÑOZ, ESTELA M.
Instituto de Histología y Embriología, Universidad Nacional de Cuyo
Lugar: Mendoza; Año: 2017 vol. 41
GABA is currently known for its dual action, inhibitory or excitatory, in the developing brain. Two types of GABA receptors mediate these actions: GABAAR and GABABR. The functional metabotropic GABABR is composed of two subunits, B1 and B2. GABA binding to B1 triggers the subsequent cellular responses via B2. Cerebellar development starts during late embryogenesis and continues postnatally (P). Previous data from our group showed a postnatal dynamism of GABAB1 in the rat cerebellum. To define the functionality of GABABR, we studied GABAB2 in cerebellum at P5, 15 and 90, performing RT-PCR, Western blot (WB) and immunohistochemistry (IHC) followed by confocal microscopy. Several cell type-specific markers were included (calbindin, NeuroD1, S100β, Iba1, GM130,calnexin and actin as internal control). Statistical analysis showed increasing levels in Gabbr2 and GABAB2 from P5 to P15, and differences in mRNA and protein expression trends at P90. GABAB2 was widely distributed in the postnatal cerebellum however the developing Purkinje cells (PkC) showed the most dynamic expression pattern in accordance with the process of terminal differentiationand maturation of these cells. GABAB2 at P5 was mainly cytoplasmic, co-localizing with calnexin and GM130, markers of endoplasmic reticulum and Golgi, respectively. From P15 onwards GABAB2 was observed as discrete granules on the surface membrane of PkC, at both the soma and dendritic tree levels. GABAB2 was also present in the granular cell lineage whereas the Begmann glia was negative.Our data suggest that GABABR mediates the postnatal development of the cerebellar cortex in a cell type-specific manner.