Anatomically and functionally distinct thalamocortical inputs to primary and secondary mouse whisker somatosensory cortices

Nat Commun. 2020 Jul 3;11(1):3342. doi: 10.1038/s41467-020-17087-7.

Abstract

Subdivisions of mouse whisker somatosensory thalamus project to cortex in a region-specific and layer-specific manner. However, a clear anatomical dissection of these pathways and their functional properties during whisker sensation is lacking. Here, we use anterograde trans-synaptic viral vectors to identify three specific thalamic subpopulations based on their connectivity with brainstem. The principal trigeminal nucleus innervates ventral posterior medial thalamus, which conveys whisker-selective tactile information to layer 4 primary somatosensory cortex that is highly sensitive to self-initiated movements. The spinal trigeminal nucleus innervates a rostral part of the posterior medial (POm) thalamus, signaling whisker-selective sensory information, as well as decision-related information during a goal-directed behavior, to layer 4 secondary somatosensory cortex. A caudal part of the POm, which apparently does not receive brainstem input, innervates layer 1 and 5A, responding with little whisker selectivity, but showing decision-related modulation. Our results suggest the existence of complementary segregated information streams to somatosensory cortices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Stem / cytology
  • Brain Stem / physiology
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Female
  • Male
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Neural Pathways / physiology*
  • Neurons / physiology
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / physiology*
  • Synaptic Transmission
  • Thalamus / cytology
  • Thalamus / physiology*
  • Touch / physiology*
  • Vibrissae / innervation
  • Vibrissae / physiology*