Laminar distribution and arbor density of two functional classes of thalamic inputs to primary visual cortex

Cell Rep. 2021 Oct 12;37(2):109826. doi: 10.1016/j.celrep.2021.109826.


Motion/direction-sensitive and location-sensitive neurons are the two major functional types in mouse visual thalamus that project to the primary visual cortex (V1). It is under debate whether motion/direction-sensitive inputs preferentially target the superficial layers in V1, as opposed to the location-sensitive inputs, which preferentially target the middle layers. Here, by using calcium imaging to measure the activity of motion/direction-sensitive and location-sensitive axons in V1, we find evidence against these cell-type-specific laminar biases at the population level. Furthermore, using an approach to reconstruct axon arbors with identified in vivo response types, we show that, at the single-axon level, the motion/direction-sensitive axons project more densely to the middle layers than the location-sensitive axons. Overall, our results demonstrate that motion/direction-sensitive thalamic neurons project extensively to the middle layers of V1 at both the population and single-cell levels, providing further insight into the organization of thalamocortical projection in the mouse visual system.

Keywords: cell types; single-axon reconstruction; spatial-function correspondence; thalamocortical.

Publication types

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

MeSH terms

  • Animals
  • Axons / physiology*
  • Calcium Signaling
  • Female
  • Male
  • Mice, Transgenic
  • Microscopy, Confocal
  • Microscopy, Fluorescence, Multiphoton
  • Motion Perception*
  • Orientation*
  • Photic Stimulation
  • Primary Visual Cortex / cytology
  • Primary Visual Cortex / physiology*
  • Thalamus / cytology
  • Thalamus / physiology*
  • Visual Pathways / cytology
  • Visual Pathways / physiology