Lateral Inhibition in the Vertebrate Retina: The Case of the Missing Neurotransmitter

PLoS Biol. 2015 Dec 10;13(12):e1002322. doi: 10.1371/journal.pbio.1002322. eCollection 2015 Dec.


Lateral inhibition at the first synapse in the retina is important for visual perception, enhancing image contrast, color discrimination, and light adaptation. Despite decades of research, the feedback signal from horizontal cells to photoreceptors that generates lateral inhibition remains uncertain. GABA, protons, or an ephaptic mechanism have all been suggested as the primary mediator of feedback. However, the complexity of the reciprocal cone to horizontal cell synapse has left the identity of the feedback signal an unsolved mystery.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Calcium Channels, N-Type / metabolism
  • Functional Laterality*
  • Humans
  • Hydrogen-Ion Concentration
  • Models, Neurological*
  • Nerve Tissue Proteins / agonists
  • Nerve Tissue Proteins / metabolism
  • Neural Inhibition*
  • Receptors, GABA / metabolism
  • Retina / cytology
  • Retina / physiology*
  • Retinal Cone Photoreceptor Cells / cytology
  • Retinal Cone Photoreceptor Cells / physiology*
  • Retinal Horizontal Cells / cytology
  • Retinal Horizontal Cells / physiology*
  • Retinal Rod Photoreceptor Cells / cytology
  • Retinal Rod Photoreceptor Cells / physiology*
  • Synaptic Transmission
  • gamma-Aminobutyric Acid / metabolism


  • Calcium Channels, N-Type
  • Nerve Tissue Proteins
  • Receptors, GABA
  • gamma-Aminobutyric Acid