The Excitatory Neuronal Network of the C2 Barrel Column in Mouse Primary Somatosensory Cortex

Neuron. 2009 Jan 29;61(2):301-16. doi: 10.1016/j.neuron.2008.12.020.

Abstract

Local microcircuits within neocortical columns form key determinants of sensory processing. Here, we investigate the excitatory synaptic neuronal network of an anatomically defined cortical column, the C2 barrel column of mouse primary somatosensory cortex. This cortical column is known to process tactile information related to the C2 whisker. Through multiple simultaneous whole-cell recordings, we quantify connectivity maps between individual excitatory neurons located across all cortical layers of the C2 barrel column. Synaptic connectivity depended strongly upon somatic laminar location of both presynaptic and postsynaptic neurons, providing definitive evidence for layer-specific signaling pathways. The strongest excitatory influence upon the cortical column was provided by presynaptic layer 4 neurons. In all layers we found rare large-amplitude synaptic connections, which are likely to contribute strongly to reliable information processing. Our data set provides the first functional description of the excitatory synaptic wiring diagram of a physiologically relevant and anatomically well-defined cortical column at single-cell resolution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Afferent Pathways / cytology
  • Afferent Pathways / physiology
  • Animals
  • Excitatory Postsynaptic Potentials / physiology
  • Fluorescent Dyes
  • Mechanoreceptors / cytology
  • Mechanoreceptors / physiology
  • Mice
  • Mice, Inbred C57BL
  • Nerve Net / cytology
  • Nerve Net / physiology*
  • Neural Pathways / cytology
  • Neural Pathways / physiology
  • Neurons / cytology
  • Neurons / physiology*
  • Organ Culture Techniques
  • Patch-Clamp Techniques
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / physiology*
  • Staining and Labeling
  • Synapses / physiology
  • Synapses / ultrastructure
  • Synaptic Transmission / physiology*
  • Touch / physiology
  • Trigeminal Nerve / cytology
  • Trigeminal Nerve / physiology
  • Vibrissae / cytology
  • Vibrissae / physiology

Substances

  • Fluorescent Dyes