Modulation of glial connectivity in the olfactory pathway

ANA PAULA PIANTANIDA; LORENA RELA

Huerta Grande, Córdoba

Congreso; XXVII Congreso Anual SAN; 2012

Sociedad Argentina de Investigación en Neurociencias

Neurogenesis in the olfactory epithelium produces olfactory sensory neurons(OSNs) throughout life. Specialized glia, olfactory ensheathing cells (OECs)support the extension of OSN axons along the olfactory nerve up to the centralnervous system where they synapse. OECs are gap junction-coupled in aselective manner, which alters their biophysical properties. In addition, OSNactivity elicits Ca2+ transients in OECs through glutamate and ATP release andCa2+ modulates gap junction permeability. Hence, we propose that signalsfrom OSNs modulate OEC gap junction coupling. The aims of this work were to:1. test whether glutamate and/or ATP modulate OECs connectivity, usingelectrophysiological techniques in olfactory bulb acute slices and 2. test whetherOEC connectivity is affected in a model of degeneration-regeneration of OSNs,analyzing the abundance of the main OEC gap junction protein connexin 43with inmunohistochemistry. We present preliminary results suggesting that ATPpromotes uncoupling of OECs and that the degeneration of OSNs correlateswith an upregulation of connexin 43 in the outer layers of the olfactory bulb. Ourpreliminary results are consistent with the inhibitory effect of ATP on astrocyticgap junction coupling and suggests that the upregulation of connexin 43observed during OSN degeneration is a compensatory effect after massive ATPrelease.