Altered balance of receptive field excitation and suppression in visual cortex of amblyopic macaque monkeys

Luke E. Hallum, Christopher Shooner, Romesh D. Kumbhani, Jenna G. Kelly, Virginia García-Marín, Najib J. Majaj, J. Anthony Movshon, Lynne Kiorpes

Research output: Contribution to journalArticlepeer-review

Abstract

In amblyopia, a visual disorder caused by abnormal visual experience during development, the amblyopic eye (AE) loses visual sensitivity whereas the fellow eye (FE) is largely unaffected. Binocular vision in amblyopes is often disrupted by interocular suppression. We used 96-electrode arrays to record neurons and neuronal groups in areas V1 and V2 of six female macaque monkeys (Macaca nemestrina) made amblyopic by artificial strabismus or anisometropia in early life, as well as two visually normal female controls. To measure suppressive binocular interactions directly, we recorded neuronal responses to dichoptic stimulation. We stimulated both eyes simultaneously with large sinusoidal gratings, controlling their contrast independently with raised-cosine modulators of different orientations and spatial frequencies. We modeled each eye’s receptive field at each cortical site using a difference of Gaussian envelopes and derived estimates of the strength of central excitation and surround suppression. We used these estimates to calculate ocular dominance separately for excitation and suppression. Excitatory drive from the FE dominated amblyopic visual cortex, especially in more severe amblyopes, but suppression from both the FE and AEs was prevalent in all animals. This imbalance created strong interocular suppression in deep amblyopes: increasing contrast in the AE decreased responses at binocular cortical sites. These response patterns reveal mechanisms that likely contribute to the interocular suppression that disrupts vision in amblyopes.

Original languageEnglish (US)
Pages (from-to)8216-8226
Number of pages11
JournalJournal of Neuroscience
Volume37
Issue number34
DOIs
StatePublished - Aug 23 2017

Keywords

  • Anisometropia
  • Binocular interaction
  • Development
  • Interocular perceptual suppression
  • Strabismus

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint

Dive into the research topics of 'Altered balance of receptive field excitation and suppression in visual cortex of amblyopic macaque monkeys'. Together they form a unique fingerprint.

Cite this