Brefeldin A ribosilation substrate (BARS) is involved in neuronal differentiation and neocortex development

MESTRES, IVAN; GASTALDI, LAURA; CONDE, CECILIA; CACERES, ALFREDO

Congreso; XXVII Congreso Anual Sociedad Argentina de Neurociencias; 2012

BARS have been reported to control vesicular traffic, including transport from the Golgi apparatus to the somatodendritic plasma membrane. By means of in utero electroporation of a short hairpin (sh) RNAi to suppress endogenous expression of BARS we have investigated its role during brain formation. In this study we show that 2 days after GFP electroporation 85% of the neurons already adopted a bipolar morphology and started to migrate along the cortical plate (CP). At the same time point only 39% of the cells expressing shBars-GFP acquired the typical bipolar form while more than 60% of them appear arrested in a multipolar typology. When examining 4 days after electroporation we found that control GFP expressing neurons have reached superficial layers of the CP whereas shBars-GFP electroporated ones remained in deeper positions. We have also examined the Golgi apparatus polarization 2 days after co-electroporation with GalT2 and found that 75% of the GFP positive neurons evidence their Golgi apparatus right at the base of the leading process that guides migration along the CP. In contrast almost 50% of shBars-GFP co-expressing neurons present this organelle opposed to their leading edge. All these evidence suggest a strong role of Bars in neuronal differentiation as well as in cortical lamination. This might be due to its role in controlling dendritic-derived membrane trafficking.