SPLTRAK Abstract Submission
P75NTR Fails to co-Localize with Neuronal Markers in the Glomerular Layer of the Mouse Olfactory Bulb
Rebecca McSorley & Tom Mast
Eastern Michigan University, Ypsilanti, MI, United States

The mouse olfactory system has demonstrated regeneration and plasticity. New sensory axons are guided by olfactory ensheathing cells (OECs), a type of glia, to the olfactory glomerulus where they synapse with mitral and tufted cells. Interestingly, activation of the pan-neurotrophin receptor (p75NTR) by pro-brain derived neurotrophin receptor reduces glomerular tyrosine hydroxylase expression. Thus, we hypothesized that p75NTR signaling in the OECs can regulate synapses within the glomerulus and induce plasticity. However, while OECs are apparent in the olfactory nerve layer, there has been discrepancy as to whether OECs can be found within the glomerular neuropil. In previous experiments we demonstrated p75NTR expression in the neuropil via immunohistochemistry and lesion studies, but were unable to define the cell type that expresses p75NTR. However, p75NTR expression was obvious near sensory axons. In the current experiment we utilize new markers for OECs—brain lipid binding protein (BLBP) and S100beta—and only find minimal co-localization. We conclude that p75NTR is expressed within the neuropil by a sub-set of OECs. Additionally, since some OECs express p75NTR, then these cells may help regulate olfactory synapses.