Abstract View

TEN_M3 IS EXPRESSED IN THE DEVELOPING VISUAL PATHWAY. C.A.Leamey1,2,4*; N.Kang2; E.Croisier1,2; K.H.Wang1,3; O.Brandau5; R.Fassler5; S.Tonegawa1,2,3; M.Sur1,2 1. Picower Ctr. for Learning and Memory, 2. Brain and Cognitive Sci., 3. Biol., MIT, Cambridge, MA, USA 4. Physiology, Univ. of Sydney, Sydney, Australia 5. Max-Planck Inst. for Biochem., Martinsreid, Germany Cortical areas are characterised by their unique patterns of connectivity and cytoarchitecture. Recently, there has been increasing evidence that intrinsic molecular cues may play an important role in the control of cortical regionalization, yet little is known about the substrates that underlie the development of the appropriate patterns of connectivity. Using microarrays, we identified a number of genes that are differentially expressed between rostral and caudal cortical regions in the neonatal mouse. One of the genes, Ten_m3, is highly expressed in caudal cortex in layer V of a region that corresponds well to visual cortex during the first postnatal week. Ten_m3 is also expressed in the developing lateral geniculate nucleus and in the ganglion cells of the ventral retina. Retrograde tracing studies from the superior colliculus showed that corticocollicular neurons expressed Ten_m3, whereas injections of tracer into the contralateral cortex showed that callosal neurons do not express the gene. Ten_m3 encodes a type II transmembrane protein, and antibody staining revealed that the protein is present not only in the somata of layer V neurons, but also along the pathway of the corticofugal axons as they descend from the cortex towards the thalamus. We have also examined the embryonic expression pattern of the gene and found that it is expressed in the developing cortical plate by embryonic day (E)16. The expression of a transmembrane protein in the axons of a specific subset of cortical projection neurons in the developing visual system is intriguing and suggests that Ten_m3 may play a regulatory role during the formation of this pathway. Support Contributed By: NIH EY14134 (MS) Citation: C.A. Leamey, N. Kang, E. Croisier, K.H. Wang, O. Brandau, R. Fassler, S. Tonegawa, M. Sur. TEN_M3 IS EXPRESSED IN THE DEVELOPING VISUAL PATHWAY. Program No. 567.19. 2003 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2003. Online.