Connexin 43 contributes to gap junction coupling in olfactory ensheathing glia

LUIS ERNESTO ACOSTA; ANA PAULA PIANTANIDA; CLAUDIA CAPURRO; LORENA RELA

Huerta Grande

Congreso; XIX Congreso Anual SAN; 2014

Sociedad Argentina de Investigación en Neurociencias

Gap junction coupling mediated by connexins is essential for glial cell functions, including potassium buffering and support for synaptic transmission. Olfactory ensheathing cells (OECs) are specialized glial cells that wrap olfactory sensory neuron axons from the olfactory epithelium to the olfactory bulb (OB) and express Cx43. We hipothesize that Cx43 mediates the formation of OEC networks important for plasticity of the olfactory nerve. Here we show that OECs located in external layers of the OB display lower immunoreactivity for Cx43 than internal OECs. This correlates with indicators of a lower degree of gap junction coupling, i.e. significantly lower membrane conductance and smaller amplitude of membrane currents sensitive for meclofenamic acid (MFA 100 μM), a gap junction blocker. We used inducible Cre-Lox technology to delete Cx43 coding sequences in OECs in juvenile or adult mice. We show that mice with the induced Cx43 deletion have OECs with significantly reduced Cx43 immunoreactivity, smaller membrane conductance and lower sensitivity to MFA, suggesting that Cx43 contributes to gap junction coupling in OECs. In addition, Cx43 deletion was not compensated by an upregulation of Cx30, a compensation that was reported in astrocytes. Our data validates the Cre-Lox system to manipulate candidate genes in OECs and establishes the context to ask questions regarding the function of Cx43 in the plasticity of the olfactory nerve.