Synaptic Transfer between Rod and Cone Pathways Mediated by AII Amacrine Cells in the Mouse Retina

Curr Biol. 2018 Sep 10;28(17):2739-2751.e3. doi: 10.1016/j.cub.2018.06.063. Epub 2018 Aug 16.


To understand computation in a neural circuit requires a complete synaptic connectivity map and a thorough grasp of the information-processing tasks performed by the circuit. Here, we dissect a microcircuit in the mouse retina in which scotopic visual information (i.e., single photon events, luminance, contrast) is encoded by rod bipolar cells (RBCs) and distributed to parallel ON and OFF cone bipolar cell (CBC) circuits via the AII amacrine cell, an inhibitory interneuron. Serial block-face electron microscopy (SBEM) reconstructions indicate that AIIs preferentially connect to one OFF CBC subtype (CBC2); paired whole-cell patch-clamp recordings demonstrate that, depending on the level of network activation, AIIs transmit distinct components of synaptic input from single RBCs to downstream ON and OFF CBCs. These findings highlight specific synaptic and circuit-level features that allow intermediate neurons (e.g., AIIs) within a microcircuit to filter and propagate information to downstream neurons.

Keywords: adaptation; bipolar; connectomics; gap junction; glycine; rectification; ribbon.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adaptation, Physiological
  • Amacrine Cells / physiology*
  • Amacrine Cells / ultrastructure
  • Animals
  • Mice
  • Nerve Net / physiology
  • Retinal Bipolar Cells / physiology
  • Retinal Bipolar Cells / ultrastructure
  • Retinal Cone Photoreceptor Cells / physiology*
  • Retinal Cone Photoreceptor Cells / ultrastructure
  • Retinal Rod Photoreceptor Cells / physiology*
  • Retinal Rod Photoreceptor Cells / ultrastructure
  • Synapses / physiology*
  • Synaptic Transmission / physiology*