Retinal origin of direction selectivity in the superior colliculus

Nat Neurosci. 2017 Apr;20(4):550-558. doi: 10.1038/nn.4498. Epub 2017 Feb 13.

Abstract

Detecting visual features in the environment, such as motion direction, is crucial for survival. The circuit mechanisms that give rise to direction selectivity in a major visual center, the superior colliculus (SC), are entirely unknown. We optogenetically isolate the retinal inputs that individual direction-selective SC neurons receive and find that they are already selective as a result of precisely converging inputs from similarly tuned retinal ganglion cells. The direction-selective retinal input is linearly amplified by intracollicular circuits without changing its preferred direction or level of selectivity. Finally, using two-photon calcium imaging, we show that SC direction selectivity is dramatically reduced in transgenic mice that have decreased retinal selectivity. Together, our studies demonstrate a retinal origin of direction selectivity in the SC and reveal a central visual deficit as a consequence of altered feature selectivity in the retina.

MeSH terms

  • Animals
  • Excitatory Postsynaptic Potentials / physiology
  • Female
  • Glutamate Decarboxylase / genetics
  • Male
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Motion Perception / physiology*
  • Neurons / physiology
  • Photic Stimulation
  • Retina / physiology*
  • Retinal Ganglion Cells / physiology
  • Superior Colliculi / physiology*
  • Vesicular Inhibitory Amino Acid Transport Proteins / genetics
  • Visual Pathways / physiology

Substances

  • Vesicular Inhibitory Amino Acid Transport Proteins
  • Viaat protein, mouse
  • Glutamate Decarboxylase
  • glutamate decarboxylase 2