Unbound MEDLINE

Alignment of multimodal sensory input in the superior colliculus through a gradient-matching mechanism.

Abstract

The superior colliculus (SC) is a midbrain structure that integrates visual, somatosensory, and auditory inputs to direct head and eye movements. Each of these modalities is topographically mapped and aligned with the others to ensure precise behavioral responses to multimodal stimuli. While it is clear that neural activity is instructive for topographic alignment of inputs from the visual cortex (V1) and auditory system with retinal axons in the SC, there is also evidence that activity-independent mechanisms are used to establish topographic alignment between modalities. Here, we show that the topography of the projection from primary somatosensory cortex (S1) to the SC is established during the first postnatal week. Unlike V1-SC projections, the S1-SC projection does not bifurcate when confronted with a duplicated retinocollicular map, showing that retinal input in the SC does not influence the topography of the S1-SC projection. However, S1-SC topography is disrupted in mice lacking ephrin-As, which we find are expressed in graded patterns along with their binding partners, the EphA4 and EphA7, in both S1 and the somatosensory recipient layer of the SC. Together, these data support a model in which somatosensory inputs into the SC map topographically and establish alignment with visual inputs in the SC using a gradient-matching mechanism.

Links

  • PMC Free PDF
  • Publisher Full Text

    • Authors

    Triplett JW, Phan A, Yamada J, Feldheim DA

    Institution

    Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California 95064, USA. JTriplett@cnmcresearch.org

    Source

    The Journal of neuroscience : the official journal of the Society for Neuroscience 32:15 2012 Apr 11 pg 5264-71

    MeSH

    Animals
    Axons
    Brain Mapping
    Ephrins
    Female
    Image Processing, Computer-Assisted
    In Situ Hybridization
    Male
    Mice
    Mice, Inbred C57BL
    Mice, Knockout
    Mice, Transgenic
    Microscopy, Fluorescence
    Motor Cortex
    Sensation
    Somatosensory Cortex
    Superior Colliculi
    Visual Cortex
    Visual Pathways

    Pub Type(s)

    Journal Article
    Research Support, N.I.H., Extramural

    Language

    eng

    PubMed ID

    22496572