Selective ablation of connexin 43 in olfactory ensheathing cells is associated to a reduction of sensory input

ANA PAULA PIANTANIDA; CLAUDIA CAPURRO; JUAN BELFORTE; LORENA RELA

Mar del Plata

Congreso; XXX Reunion Anual; 2015

Sociedad Argentina de Investigacion en Neurociencias

The olfactory epithelium produces olfactory sensory neurons (OSNs) throughout life.Permissivity for OSN turnover is attributed to glial cells, olfactory ensheathing cells (OECs)which can promote axon growth in vitro and when transplanted in vivo to injury sites.However the mechanism rests unknown due to the limited knowledge of OEC physiology.We previously reported that OECs are gap junction-coupled and express connexin 43(Cx43). We propose that OSN incorporation to the circuit depends on functional OECnetworks involving Cx43. To test this, we used inducible Cre-Lox technology to delete Cx43sequences in OECs of adult mice to: 1) characterize electrophysiological indicators of OECcoupling and 2) evaluate indicators of sensory input. OECs with reduced expression of Cx43showed smaller amplitude membrane currents, lower conductance and lower sensitivity toa gap junction blocker. Also, bulbs of mice with Cx43 deletion displayed lower numbers oftyrosine hydroxylase positive interneurons, indicating a weaker sensory input. Finally, toassess the effect of OEC disconnection on olfactory function we performed a habituationdishabituationtest. Preliminary results suggest a reduced sensitivity to opposite-sex socialodors in Cx43-deleted mice. In summary, our results support that Cx43 is a key mediator ofOEC coupling, and present a model to understand the role of OEC connectivity on themaintenance of the olfactory pathway and to explore the regenerative potential of OECs.