A molecular mechanism for the topographic alignment of convergent neural maps.
Sensory processing requires proper alignment of neural maps throughout the brain. In the superficial layers of the superior colliculus of the midbrain, converging projections from retinal ganglion cells and neurons in visual cortex must be aligned to form a visuotopic map, but the basic mechanisms mediating this alignment remain elusive. In a new mouse model, ectopic expression of ephrin-A3 (Efna3) in a subset of retinal ganglion cells, quantitatively altering the retinal EFNAs gradient, disrupts cortico-collicular map alignment onto the retino-collicular map, creating a visuotopic mismatch. Genetic inactivation of ectopic EFNA3 restores a wild-type cortico-collicular map. Theoretical analyses using a new mapping algorithm model both map formation and alignment, and recapitulate our experimental observations. The algorithm is based on an initial sensory map, the retino-collicular map, which carries intrinsic topographic information, the retinal EFNAs, to the superior colliculus. These EFNAs subsequently topographically align ingrowing visual cortical axons to the retino-collicular map.
CNRS UPR3212 - Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France.
Elise
0000-0001-7512-1630
E
Savier
Department of Applied Mathematics and Theoretical Physics, Cambridge Computational Biology Institute, University of Cambridge, Cambridge, United Kingdom.|University of Strasbourg Institute of Advanced Study, Strasbourg, France.
Stephen J
0000-0001-8607-8025
SJ
Eglen
CNRS UPR3212 - Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France.
Amélie
A
Bathélémy
CNRS UPR3212 - Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France.
Martine
M
Perraut
CNRS UPR3212 - Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France.
Frank W
FW
Pfrieger
Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, San Diego, United States.
Greg
G
Lemke
CNRS UPR3212 - Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France.|University of Strasbourg Institute of Advanced Study, Strasbourg, France.
Michael
0000-0001-8842-7276
M
Reber
D000818:Animals; D001369:Axons / Q000502:physiology*; D001931:Brain Mapping; D051379:Mice; D012165:Retinal Ganglion Cells / Q000502:physiology*; D013477:Superior Colliculi / Q000033:anatomy & histology / Q000502:physiology*; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology*
EphA/ephrin-As; computational biology; computational model; mouse; neuroscience; sensory map; systems biology; visual network