The functional asymmetry of auditory cortex is reflected in the organization of local cortical circuits

Nat Neurosci. 2010 Nov;13(11):1413-20. doi: 10.1038/nn.2659. Epub 2010 Oct 17.


The primary auditory cortex (A1) is organized tonotopically, with neurons sensitive to high and low frequencies arranged in a rostro-caudal gradient. We used laser scanning photostimulation in acute slices to study the organization of local excitatory connections onto layers 2 and 3 (L2/3) of the mouse A1. Consistent with the organization of other cortical regions, synaptic inputs along the isofrequency axis (orthogonal to the tonotopic axis) arose predominantly within a column. By contrast, we found that local connections along the tonotopic axis differed from those along the isofrequency axis: some input pathways to L3 (but not L2) arose predominantly out-of-column. In vivo cell-attached recordings revealed differences between the sound-responsiveness of neurons in L2 and L3. Our results are consistent with the hypothesis that auditory cortical microcircuitry is specialized to the one-dimensional representation of frequency in the auditory cortex.

Publication types

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

MeSH terms

  • Acoustic Stimulation / methods
  • Adjuvants, Immunologic / pharmacology
  • Amino Acids / metabolism
  • Animals
  • Animals, Newborn
  • Anisotropy
  • Auditory Cortex / cytology
  • Auditory Cortex / physiology*
  • Brain Mapping*
  • Cholera Toxin / pharmacology
  • Excitatory Postsynaptic Potentials / physiology
  • Functional Laterality / physiology*
  • Glutamic Acid / metabolism
  • In Vitro Techniques
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Microscopy, Confocal / methods
  • Nerve Net / physiology*
  • Neural Pathways / physiology
  • Neurons / physiology*
  • Photic Stimulation / methods
  • Psychoacoustics
  • Rats
  • Rats, Long-Evans
  • Statistics, Nonparametric
  • Time Factors


  • Adjuvants, Immunologic
  • Amino Acids
  • dolaisoleucine
  • Glutamic Acid
  • Cholera Toxin