Participation of glia in the post-natal refinement of the olfactory bulb sensory map

LUCILA BROCARDO; LUIS ERNESTO ACOSTA; LORENA RELA

Mar del Plata

Congreso; XXX Reunion Anual; 2015

Sociedad Argentina de Investigacion en Neurociencias

The olfactory system of rodents is host to a special type of glia, the olfactory ensheathingcells (OECs), which evidence a high degree of gap junction connectivity. In addition, in theolfactory bulb post-natal refinement of the topographic innervation from olfactory sensoryneurons occurs, yet no studies exist in regards to post-natal changes in glial networkarchitecture. We propose that a simultaneous refinement of glial connectivity occurs, andlike the neuronal counterpart, it depends on sensory experience. Moreover, OECs areattributed to providing the appropriate environment for olfactory sensory neuron turnoverand regeneration, partly through expression of neurotrophins. The neurotrophin BDNFallows the expression of axonal competence for the establishment of stable connections inthe olfactory bulb. Therefore, our hypothesis is that BDNF released from olfactoryensheathing cells participates in the post-natal maturation of the sensory map. Ourapproach is the generation of an in vivo mouse model that applies the Cre-lox technologyto delete coding regions for BDNF in OECs with time control. We use morphological,histochemical, electrophysiological and genetic techniques to evaluate whether thematuration of olfactory circuits and/or glial networks are deficient in these mice. We showpreliminary expression profiles of connexins 30 and 43, as an early approach to glialconnectivity, and raise the question whether there is a connexin switch during refinement.