title: An NMDA receptor-dependent mechanism for subcellular segregation of sensory inputs in the tadpole optic tectum.
abstract: In the vertebrate CNS, afferent sensory inputs are targeted to specific depths or layers of their target neuropil. This patterning exists ab initio, from the very beginning, and therefore has been considered an activity-independent process. However, here we report that, during circuit development, the subcellular segregation of the visual and mechanosensory inputs to specific regions of tectal neuron dendrites in the tadpole optic tectum requires NMDA receptor activity. Blocking NMDARs during the formation of these sensory circuits, or removing the visual set of inputs, leads to less defined segregation, and suggests a correlation-based mechanism in which correlated inputs wire to common regions of dendrites. This can account for how two sets of inputs form synapses onto different regions of the same dendrite. Blocking NMDA receptors during later stages of circuit development did not disrupt segregation, indicating a critical period for activity-dependent shaping of patterns of innervation.
authors.affiliation: Department of Zoology and Physiology and Program in Neuroscience, University of Wyoming, Laramie, United States.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Hamodi
authors.affiliation: Department of Zoology and Physiology and Program in Neuroscience, University of Wyoming, Laramie, United States.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Zoology and Physiology and Program in Neuroscience, University of Wyoming, Laramie, United States.
authors.forename: Kara G
authors.identifier: 0000-0002-6743-4757
authors.initials: KG
authors.lastname: Pratt
mesh_terms: D000818:Animals; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D015870:Gene Expression; D007814:Larva / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics*; D019581:Neuropil / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013477:Superior Colliculi / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D055366:Synaptic Potentials / Q000187:drug effects / Q000502:physiology; D014982:Xenopus laevis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate
keywords: NMDA receptor; activity-dependent; axon segregation; multisensory; neuroscience; optic tectum; subcellular; xenopus