title: A synaptic strategy for consolidation of convergent visuotopic maps.
abstract: The mechanisms by which experience guides refinement of converging afferent pathways are poorly understood. We describe a vision-driven refinement of corticocollicular inputs that determines the consolidation of retinal and visual cortical (VC) synapses on individual neurons in the superficial superior colliculus (sSC). Highly refined corticocollicular terminals form 1-2 days after eye-opening (EO), accompanied by VC-dependent filopodia sprouting on proximal dendrites, and PSD-95 and VC-dependent quadrupling of functional synapses. Delayed EO eliminates synapses, corticocollicular terminals, and spines on VC-recipient dendrites. Awake recordings after EO show that VC and retina cooperate to activate sSC neurons, and VC light responses precede sSC responses within intervals promoting potentiation. Eyelid closure is associated with more protracted cortical visual responses, causing the majority of VC spikes to follow those of the colliculus. These data implicate spike-timing plasticity as a mechanism for cortical input survival, and support a cooperative strategy for retinal and cortical coinnervation of the sSC.
authors.affiliation: McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. marnie.a.phillips@gmail.com
authors.forename: Marnie A
authors.initials: MA
authors.lastname: Phillips
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Colonnese
authors.forename: Julie
authors.initials: J
authors.lastname: Goldberg
authors.forename: Laura D
authors.initials: LD
authors.lastname: Lewis
authors.forename: Emery N
authors.initials: EN
authors.lastname: Brown
authors.forename: Martha
authors.initials: M
authors.lastname: Constantine-Paton
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000344:Afferent Pathways / Q000033:anatomy & histology / Q000502:physiology; D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D003712:Dendrites / Q000502:physiology / Q000648:ultrastructure; D000076122:Disks Large Homolog 4 Protein; D051528:Guanylate Kinases; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology / Q000502:physiology; D018408:Patch-Clamp Techniques; D011554:Pseudopodia / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000166:cytology / Q000502:physiology; D013477:Superior Colliculi / Q000033:anatomy & histology* / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology; D014795:Visual Pathways / Q000033:anatomy & histology* / Q000502:physiology*
chemical_list: D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D008565:Membrane Proteins; D051528:Guanylate Kinases