title: The Regulation of Corticofugal Fiber Targeting by Retinal Inputs.
abstract: Corticothalamic projection systems arise from 2 main cortical layers. Layer V neurons project exclusively to higher-order thalamic nuclei, while layer VIa fibers project to both first-order and higher-order thalamic nuclei. During early postnatal development, layer VIa and VIb fibers accumulate at the borders of the dorsal lateral geniculate nucleus (dLGN) before they innervate it. After neonatal monocular enucleation or silencing of the early retinal activity, there is premature entry of layer VIa and VIb fibers into the dLGN contralateral to the manipulation. Layer V fibers do not innervate the superficial gray layer of the superior colliculus during the first postnatal week, but also demonstrate premature entry to the contralateral superficial gray layer following neonatal enucleation. Normally, layer V driver projections to the thalamus only innervate higher-order nuclei. Our results demonstrate that removal of retinal input from the dLGN induces cortical layer V projections to aberrantly enter, arborize, and synapse within the first-order dLGN. These results suggest that there is cross-hierarchical corticothalamic plasticity after monocular enucleation. Cross-hierarchical rewiring has been previously demonstrated in the thalamocortical system (Pouchelon et al. 2014), and now we provide evidence for cross-hierarchical corticothalamic rewiring after loss of the peripheral sensory input.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Grant
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Hoerder-Suabedissen
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Molnár
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D049108:Cell Enlargement; D002540:Cerebral Cortex / Q000166:cytology / Q000254:growth & development* / Q000502:physiology; D007150:Immunohistochemistry; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D018722:Nicotinic Agonists / Q000494:pharmacology; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D011725:Pyridines / Q000494:pharmacology; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D016708:Synaptophysin / Q000378:metabolism; D013787:Thalamic Nuclei / Q000166:cytology / Q000254:growth & development* / Q000502:physiology; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D018722:Nicotinic Agonists; D011725:Pyridines; C493465:Slc17a7 protein, mouse; D016708:Synaptophysin; C569015:Syp protein, mouse; D050598:Vesicular Glutamate Transport Protein 1; C082748:epibatidine
keywords: cortical layer V, VIa, VIb; corticothalamic projections; cross-hierarchical plasticity; dorsal lateral geniculate nucleus; monocular enucleation