title: On and off retinal circuit assembly by divergent molecular mechanisms.
abstract: Direction-selective responses to motion can be to the onset (On) or cessation (Off) of illumination. Here, we show that the transmembrane protein semaphorin 6A and its receptor plexin A2 are critical for achieving radially symmetric arborization of On starburst amacrine cell (SAC) dendrites and normal SAC stratification in the mouse retina. Plexin A2 is expressed in both On and Off SACs; however, semaphorin 6A is expressed in On SACs. Specific On-Off bistratified direction-selective ganglion cells in semaphorin 6A(-/-) mutants exhibit decreased tuning of On directional motion responses. These results correlate the elaboration of symmetric SAC dendritic morphology and asymmetric responses to motion, shedding light on the development of visual pathways that use the same cell types for divergent outputs.
authors.affiliation: Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Lu O
authors.initials: LO
authors.lastname: Sun
authors.forename: Zheng
authors.initials: Z
authors.lastname: Jiang
authors.forename: Michal
authors.initials: M
authors.lastname: Rivlin-Etzion
authors.forename: Randal
authors.initials: R
authors.lastname: Hand
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Brady
authors.forename: Ryota L
authors.initials: RL
authors.lastname: Matsuoka
authors.forename: King-Wai
authors.initials: KW
authors.lastname: Yau
authors.forename: Marla B
authors.initials: MB
authors.lastname: Feller
authors.forename: Alex L
authors.initials: AL
authors.lastname: Kolodkin
mesh_terms: D025042:Amacrine Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D003712:Dendrites / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008817:Mice, Mutant Strains; D009038:Motion; D009039:Motion Perception; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000378:metabolism / Q000502:physiology*; D039961:Semaphorins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D009419:Nerve Tissue Proteins; C492113:Plxna2 protein, mouse; D011956:Receptors, Cell Surface; C504203:Sema6a protein, mouse; D039961:Semaphorins