A Transient Translaminar GABAergic Interneuron Circuit Connects Thalamocortical Recipient Layers in Neonatal Somatosensory Cortex

Neuron. 2016 Feb 3;89(3):536-49. doi: 10.1016/j.neuron.2016.01.015.


GABAergic activity is thought to influence developing neocortical sensory circuits. Yet the late postnatal maturation of local layer (L)4 circuits suggests alternate sources of GABAergic control in nascent thalamocortical networks. We show that a population of L5b, somatostatin (SST)-positive interneuron receives early thalamic synaptic input and, using laser-scanning photostimulation, identify an early transient circuit between these cells and L4 spiny stellates (SSNs) that disappears by the end of the L4 critical period. Sensory perturbation disrupts the transition to a local GABAergic circuit, suggesting a link between translaminar and local control of SSNs. Conditional silencing of SST+ interneurons or conversely biasing the circuit toward local inhibition by overexpression of neuregulin-1 type 1 results in an absence of early L5b GABAergic input in mutants and delayed thalamic innervation of SSNs. These data identify a role for L5b SST+ interneurons in the control of SSNs in the early postnatal neocortex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electric Stimulation
  • Female
  • Interneurons / physiology*
  • Male
  • Membrane Potentials / physiology
  • Mice
  • Mice, Transgenic
  • Neural Pathways
  • Neuregulin-1 / biosynthesis
  • Photic Stimulation
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / growth & development
  • Somatosensory Cortex / physiology*
  • Somatostatin / physiology
  • Thalamus / cytology*
  • Thalamus / physiology*
  • gamma-Aminobutyric Acid / physiology*


  • Neuregulin-1
  • Nrg1 protein, mouse
  • Somatostatin
  • gamma-Aminobutyric Acid