Cerebral Cortex Advance Access published online on November 5, 2009
Cerebral Cortex, doi:10.1093/cercor/bhp246
Developmental Expression of the Oligodendrocyte Myelin Glycoprotein in the Mouse Telencephalon
1 Molecular and Cellular Neurobiotechnology laboratory, Institute for Bioengineering of Catalonia (IBEC), Barcelona E-08028, Spain, 2 Cellular and Molecular Basis of Neurodegeneration and Neurorepair (CMBNN), Department of Cell Biology, University of Barcelona, Barcelona E-08028, Spain, 3 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid E-28031, Spain, 4 Department of Neurosciences, University of California, San Diego, CA 92093-0691, USA, 5 Neuroengineering group, Institute for Bioengineering of Catalonia (IBEC), Barcelona E-08028, Spain, 6 Neurobiology of Development and Regeneration Laboratory, Institute for Research in Biomedicine of Barcelona and Department of Cell Biology, University of Barcelona, Barcelona E-08028, Spain, 7 Institute of Predictive and Personalized Medicine of Cancer, Badalona E-08916, Spain
Address correspondence to J.A. del Río, Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, University of Barcelona, Baldiri Reixac 15-21, E-08028 Barcelona, Spain. Email: jadelrio{at}ibec.pcb.ub.es
The oligodendrocyte myelin glycoprotein is a glycosylphosphatidylinositol-anchored protein expressed by neurons and oligodendrocytes in the central nervous system. Attempts have been made to identify the functions of the myelin-associated inhibitory proteins (MAIPs) after axonal lesion or in neurodegeneration. However, the developmental roles of some of these proteins and their receptors remain elusive. Recent studies indicate that NgR1 and the recently discovered receptor PirB restrict cortical synaptic plasticity. However, the putative factors that trigger these effects are unknown. Because Nogo-A is mostly associated with the endoplasmic reticulum and myelin associated glycoprotein appears late during development, the putative participation of OMgp should be considered. Here, we examine the pattern of development of OMgp immunoreactive elements during mouse telencephalic development. OMgp immunoreactivity in the developing cortex follows the establishment of the thalamo-cortical barrel field. At the cellular level, we located OMgp neuronal membranes in dendrites and axons as well as in brain synaptosome fractions and axon varicosities. Lastly, the analysis of the barrel field in OMgp-deficient mice revealed that although thalamo-cortical connections were formed, their targeting in layer IV was altered, and numerous axons ectopically invaded layers II–III. Our data support the idea that early expressed MAIPs play an active role during development and point to OMgp participating in thalamo-cortical connections.
Key Words: axon plasticity • barrel-field specification • cortical lamination • myelin