Projection-Specific Visual Feature Encoding by Layer 5 Cortical Subnetworks

Cell Rep. 2016 Mar 22;14(11):2538-45. doi: 10.1016/j.celrep.2016.02.050. Epub 2016 Mar 10.

Abstract

Primary neocortical sensory areas act as central hubs, distributing afferent information to numerous cortical and subcortical structures. However, it remains unclear whether each downstream target receives a distinct version of sensory information. We used in vivo calcium imaging combined with retrograde tracing to monitor visual response properties of three distinct subpopulations of projection neurons in primary visual cortex. Although there is overlap across the groups, on average, corticotectal (CT) cells exhibit lower contrast thresholds and broader tuning for orientation and spatial frequency in comparison to corticostriatal (CS) cells, whereas corticocortical (CC) cells have intermediate properties. Noise correlational analyses support the hypothesis that CT cells integrate information across diverse layer 5 populations, whereas CS and CC cells form more selectively interconnected groups. Overall, our findings demonstrate the existence of functional subnetworks within layer 5 that may differentially route visual information to behaviorally relevant downstream targets.

Publication types

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

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Fluorescent Dyes / chemistry
  • In Vitro Techniques
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Fluorescence
  • Patch-Clamp Techniques
  • Photic Stimulation
  • Plasmids / metabolism
  • Synapsins / genetics
  • Visual Cortex / metabolism*
  • Visual Cortex / pathology

Substances

  • Fluorescent Dyes
  • Synapsins
  • Calcium