A role for glial connexins in the incorporation of new neurons into the olfactory pathway

LUIS ERNESTO ACOSTA; LORENA RELA

Huerta Grande, Córdoba

Congreso; XXVII Congreso Anual SAN; 2012

Sociedad Argentina de Investigación en Neurociencias

The rodent olfactory epithelium (OE) is capable of sustained neurogenesis,beginning during embryogenesis and continuing throughout adulthood.Formation of neural circuitry involves the ability of a neuron to detect andprocess cues from glia among other factors. Olfactory ensheathing cells (OECs)are specialized glial cells only present in the afferent olfactory pathway (AOP),which constitute a glial network connected by gap junction (GJ) proteins namedconnexins (Cxs). OECs promote axon growth both in vitro and in vivo, an effectthat is Ca2+-dependent. Given that Ca2+ is a modulator of GJ permeability, wehypothesize that alterations in OECs GJ connectivity affect the way that newneurons incorporate into the AOP. Our aim is to study the incorporation of newolfactory sensory neurons (OSNs) in a transgenic mouse model with reducedexpression of OEC connexins during late postnatal development. To do this, wecharacterize neurogenesis in the OE, we measure the levels of Tyrosinehydroxylase (TH) in olfactory bulb interneurons which are modulated by sensoryinput, and we quantify the levels of vesicular glutamate transporter (VGLUT2)which is strongly expressed in axon terminals of OSNs. Preliminary resultssuggest a decrease in the number of TH positive interneurons with nomodification in VGLUT2. Our results are compatible with a reduction in OSNsactivity, a reduction in OSN number, or both, as a result of the reduction of glialconnexins.