Uses and limitations of BrdU technique for the study of olfactory neurogenesis in amphibians

RAICES, M; JUNGBLUT LD; PAZ DA; POZZI AG

Huerta Grande

Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2013

The 5-bromo-2'-deoxyuridine (BrdU), is a thymidine analogue that incorporates into the DNA of dividing cells during the S-phase of the cell cycle. This analogue is widely used for the study of mitosis and cell lineage in vitro and in vivo. However, some reports questioned the validity of the use of BrdU in biological systems where this molecule shows cellular toxicity. In the present work we examined the validity of the BrdU incorporation technique for studying cell proliferation and differentiation in the olfactory epithelium (OE) in an amphibian model. Using 10 mM of BrdU, we found an increase in the number of apoptotic cells and an alteration of redox balance within the EO. We also observed a variation in the expression of different cellular markers in both olfactory receptor neurons (ORNs) and supporting cells (SCs). Moreover, the histochemical analysis showed alterations in the secretory vesicles of substentacular cells. The use of lower concentrations of BrdU (0,1 mM and 1 mM), showed that: 1) 0,1 mM was not enough to be detected by immunohistochemistry and 2) 1 mM reduced the adverse effects caused by higher concentrations, however, we observed alterations in the pattern of differentiation of the NRO. We conclude that BrdU can be successfully used as a marker of cell proliferation in the EO, but it is not appropriate for studying cell lineage because it have toxic effects on cells where is incorporated, as well as in neighboring cells.