AMIGO2 Scales Dendrite Arbors in the Retina

Cell Rep. 2019 Nov 5;29(6):1568-1578.e4. doi: 10.1016/j.celrep.2019.09.085.

Abstract

The size of dendrite arbors shapes their function and differs vastly between neuron types. The signals that control dendritic arbor size remain obscure. Here, we find that in the retina, starburst amacrine cells (SACs) and rod bipolar cells (RBCs) express the homophilic cell-surface protein AMIGO2. In Amigo2 knockout (KO) mice, SAC and RBC dendrites expand while arbors of other retinal neurons remain stable. SAC dendrites are divided into a central input region and a peripheral output region that provides asymmetric inhibition to direction-selective ganglion cells (DSGCs). Input and output compartments scale precisely with increased arbor size in Amigo2 KO mice, and SAC dendrites maintain asymmetric connectivity with DSGCs. Increased coverage of SAC dendrites is accompanied by increased direction selectivity of DSGCs without changes to other ganglion cells. Our results identify AMIGO2 as a cell-type-specific dendritic scaling factor and link dendrite size and coverage to visual feature detection.

Keywords: LRR; dendrites; development; direction selectivity; leucine-rich repeat protein; retina; rod bipolar cell; starburst amacrine cell.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Amacrine Cells / cytology*
  • Amacrine Cells / metabolism
  • Animals
  • Dendrites / genetics*
  • Dendrites / metabolism
  • Dendrites / physiology
  • Gene Knockout Techniques
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neuronal Plasticity / physiology*
  • Retina / growth & development
  • Retina / metabolism*
  • Retinal Bipolar Cells / cytology*
  • Retinal Bipolar Cells / metabolism
  • Retinal Ganglion Cells / cytology
  • Retinal Ganglion Cells / metabolism
  • Retinal Ganglion Cells / physiology
  • Synapses / genetics
  • Synapses / physiology

Substances

  • Amigo2 protein, mouse
  • Membrane Proteins
  • Nerve Tissue Proteins