Time-variant structure of auditory cortex of the macaque monkey.
Supra-threshold responses of neurons in the primary auditory cortex of the macaque monkey are so complex that the characteristic frequency cannot be determined. By statistical analyses based on analysis of variance and principal component analysis, we demonstrated that the similarity of neurons from penetration perpendicular to the surface of the cortex decreases to such a level that they cannot be considered as a unit and that correlation among neurons from different cortical positions can be higher than that for neurons from penetration. This means that the frequency map is not evident for stimuli at supra-threshold. Moreover, we found that a single neuron utilizes different time segments to extract different physical aspects of stimuli. Our results indicate that encoding auditory information may involve other structures than the frequency map.
Takahashi
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Laboratory for Neural Networks, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D008251:Macaca; D008433:Mathematics; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D013016:Sound; D013997:Time Factors